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NO.  95-82372 


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Author: 


Lehmann,  Helen  Mary 


Title: 


Glass  and  glassware 


Place: 


New  York 

Date: 

1922 


i 


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MASTER   NEGATIVE   # 


COLUMBIA  UNIVERSITY  LIBRARIES 
PRESERVATION  DIVISION 

BIBLIOGRAPHIC  MICROFORM  TARGET 


ORIGINAL  MATERIAL  AS  FILMED  -    EXISTING  BIBLIOGRAPHIC  RECORD 


254.53 


Lehmann,  Helen  Mary,  1883- 

...  Glnss  nnd  .s»]nss\v;iro,  by  IToleu  Marv  Lohmaini  ... 
mi(]  Bciilnli  Elffolli  Kcimard  ...  Now  York,  Tho  Ronald 
pross  ('oiMpaiiy,  1922. 

xvii.  221   i>.     front.,  illiis.,  plates.     \W"*.     (Merchandise  manual  series) 

Publislicd  1918  as  one  of  the  Department  store  merchandise  manuals  under 
the  title  The  glassware  department,  by  Mary  A.  Lehmann. 
"Books  for  reference":  p.  211. 


1.  Glassware.     2,  (llass  manufacture. 
1867-         joint  author,    ii.  Title. 


Library  of  Congress 
Copy  right    A  692707 


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THE  LIBRARIES 


GRADUATE 

SCHOOL  OF  BUSINESS 

LIBRARY 


Courtesy  of  United   States  Glass  Co. 

Forming  the  Stem  of  a  Goblet   (upper) 
Finished  Goblet  Ready  for  Annealing  (lower) 


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MERCHANDISE  MANUAL  SERIES 


GLASS  AND  GLASSWARE 


BY 

HELEN  MARY  LEHMANN,  B.A. 

Editorial  Staff,  Dry  Goods  Economist:  formerly  Instructor  in 

Merchandise,  New  York  City  Department  Stores,  Texas 

State  University,  and  New  York  University 

AND 
BEULAH  ELFRETH  KENNARD.  M.A. 

Editor  of  Series;  formerly  Director  of  Department  Store  Courses, 

New  York  University;  Chairman  of  Committee  on  Merchandise 

Courses  for  New  York  City  Public  Schools ;  Educational  Director. 

Department  Store  Education  Association 


NEW  YORK 
THE  RONALD  PRESS  COMPANY 

192a 


) 


Copyright,  1918,  by 
The  Ronald  Press  Company 


Copyright,  1922,  by 

The  Ronald  Press  Company 

AU  rights  reserved 


r- 


5  2-3 


(* 


flli^it  §ptxit%  i%  3iebtcateti 

to  Mrs.  Henry  Ollesheimer,  Miss 
Virginia  Potter,  and  Miss  Anne 
Morgan,  who  desiring  to  give 
greater  opportunity  for  advance- 
ment to  commercial  employees  and 
believing  that  all  business  efficiency 
must  rest  upon  a  soUd  foundation 
of  training  and  education  gave 
years  of  enthusiastic  service  to  the 
testing  of  this  belief. 


9 


1 


MERCHANDISE  MANUAL  SERIES 

EDITOR  OF  SERIES 

BEULAH  ELFRETH  KENNARD,  M.A. 

Formerly  Director  of  Department  Store  Courses,  New  York 

University:  Chairman  of  Committee  on  Merchandise  Courses 

for  New  York  City  Public  Schools;   Educational  Director, 

Department  Store  Education  Association 

CONSULTING  EDITOR 

LEE  GALLOWAY,  Ph.D. 

Professor  of  Commerce  and  Industry,  Head  of  Department 
of  Management,  and  formerly  Director  of  Training  School 
for  Teachers  of  Retail  Selling,  New  York  University  : 
formerly    Educational    Director,  the    National   Commercial 

Gas  Association 


EDITOR'S   PREFACE 

As  "Department  Store  Merchandise  Manuals"  these 
books  were  originally  written  for  salespeople  and  were 
designed  to  give  them  reliable  information  concerning 
the  sources  and  manufacturing  processes  of  the  mer- 
chandise which  they  handle.  When  it  was  necessary 
to  deal  with  scientific  or  historical  material  it  was 
treated  as  simply  and  concretely  as  possible  and  the 
point  of  view  taken  was  that  of  business  rather  than 
that  of  the  school  or  laboratory.  In  this  form  they 
have  proved  their  practical  value  not  only  to  the  de- 
partment store  salesperson  but  in  the  specialty  shop. 
It  has  been  pointed  out,  however,  that  the  material  has 
a  wider  scope  than  that  of  sales  manuals  alone. 

As  reference  books,  librarians  will  find  the  short, 
clear  statements  and  full  indexes  invaluable. 

As  an  encyclopaedia  of  merchandise  the  series  con- 
tains scientific  information  in  a  simple,  compact  form 
which  makes  it  available  for  children  and  others  to 
whom  the  subjects  treated  are  unfamiliar. 

As  textbooks  they  are  adapted  for  use  in  commercial 
schools,  high  schools,  night  schools,  settlement  classes, 
and  by  teachers  of  household  arts  and  domestic  science. 


VI 


EDITOR'S  PREFACE 


As  source  books  for  practical  story-telling,  kinder- 
gartners,  primary  and  vacation  school  teachers  will 
find  in  them  an  abundance  of  interesting  material  for 
short  "true"  stories  on  the  various  industries  and  crafts, 
the  manufacture  of  household  articles,  such  as  pins 
and  needles,  as  well  as  the  making  of  pottery,  glass,  and 
steel.  These  manuals  contain  just  the  material  often 
hunted  for  in  vain  by  teachers  and  librarians. 

As  household  helps  and  shopping  guides  the  young 
housekeeper  will  find  the  manuals  her  best  friends  be- 
cause they  not  only  describe  the  manufacturing  pro- 
cesses but  tell  her  how  to  distinguish  well-made  articles 
of  good  materials  from  the  inferior  and  badly  made. 
They  also  tell  her  how  to  care  for  the  clothing  or 
household  goods  which  she  has  bought. 

For  salespeople  and  storekeepers  they  supply  the 
general  and  specific  information  about  their  merchan- 
dise which  is  indispensable  to  efficiency,  yet  very 
hard  to  gather  from  the  scattered  sources  upon  which 
they  now  depend. 

These  changes  should  enlarge  the  usefulness  of  the 
manuals  without  losing  any  of  their  specific  value  in 
the  field  of  salesmanship. 

We  wish  to  express  our  grateful  appreciation  to  the 
manufacturers  and  experts  who  have  given  us  such 
valuable  counsel  and  cordial  co-operation. 

Beulah  Elfreth  Kennard. 


i 


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if 


AUTHORS'  PREFACE 

Glass  is  among  the  major  forms  of  merchandise. 
It  enters  into  so  many  of  the  articles  commonly  used 
in  the  household  that  it  is  practically  an  indispensable 
material.  In  table  and  kitchenware,  in  toilet  articles 
and  in  ornaments,  for  mirrors  and  for  windows,  glass 
is  found  to  be  either  the  best  substance  for  the  purpose, 
or  in  many  cases  the  only  one  that  will  serve.  A 
knowledge  of  its  sources,  manufacture,  and  qualities 
is  as  valuable  and  interesting  as  a  knowledge  of  textiles. 
If  one  is  buying  or  selling  glass,  such  knowledge  is 
necessary  for  efficiency,  but  the  student  of  chemistry, 
electricity,  or  applied  science,  and  the  artistic  craftsman 
will  find  it  equally  important  in  his  work. 

In  order  to  touch  upon  some  of  the  uses  of  glass 
outside  of  the  Glassware  Department,  but  of  prime 
importance  and  interest  to  the  student  and  general 
reader,  a  section  devoted  to  lamps,  windows,  stained 
glass,  and  optical  glass  has  been  added. 

The  authors  are  indebted  to  Mr.  Frank  E.  Freese 
of  the  United  States  Glass  Co.  for  reviewing  the  sec- 
tion on  manufacture  of  glass;  to  Mr.  E.  W.  Bryce, 

vu 


i  U 


VUl 


AUTHORS^  PREFACE 


Superintendent  of  Factory  B,  United  States  Glass  Co., 
for  valuable  notes  on  manufacture ;  to  Mr.  A.  Douglas 
Nash,  Secretary,  Treasurer,  and  Assistant  Manager 
of  the  Tiffany  Furnaces,  for  reviewing  the  chapter  on 
Tiffany  glass  and  contributing  the  section  on  peacock 
glass;  to  C.  Dorflinger  &  Sons  and  to  Mr.  G.  M.  Jaques 
of  The  Crockery  and  Glass  Journal  for  reviewing  the 
parts  on  tableware  and  cut  glass ;  to  L.  Solomon  &  Son 
for  reviewing  the  chapter  on  silver  deposit  ware;  to 
Mr.  Howard  J.  Wilbert  of  the  Pittsburgh  Art  Glass 
Co.  and  to  Mr.  Charles  J.  Connick  of  Boston,  for 
most  valuable  assistance  and  criticism  and  for  the 
illustrations  of  windows  and  stained  glass;  and  to 
Mr.  E.  Y.  Davidson,  of  the  Macbeth-Evans  Glass  Co., 
for  reviewing  the  chapter  on  "Lamps  and  Lampshades" 
and  adding  the  material  on  daylight  glass. 

For  illustrations  thanks  are  due  to  C.  Dorflinger 
&  Sons,  United  States  Glass  Co.,  A.  Gredelue,  and 
to  Pittsburgh  Art  Glass  Co. 

Helen  Mary  Lehmann- 
Beulah  Elfreth  Kennard. 


i  ' 


CONTENTS 


CHAPTER 

I    The  Glassware  Department   .     . 

Effective  Display 

Divisions  of  the  Glassware  Department 

Characteristics  of  Glass 

Utility 

Durability 

Beauty 


PAGE 

I 


PART  I  —  MANUFACTURE  OF  GLASS 


II    Glass  Materials 


f 


{ 


Nature  and  Composition 

Difference  Between  Precious  Stones  and  Glass 

Materials  of  Which  Glass  Is  Composed 

Sand 

Occurrence  of  Sand 

Quality  of  Sand  Depends  on  Constituents 

Sand  Beds 

Sandstone 

Quartz 

Flint 

Kelp  or  Seaweed 

Alkalies 

Potash 

American  Potash 

Soda 

Soda-Ash 

Salt-Cake 

Chile  Saltpeter 

Lead  and  Lime 

Forms  of  Lead  Used 

ix 


»i 


CHAPTER 


PAGE 


III 


20 


CONTENTS 

Kinds  of  Lime  Used 
Other  Materials  Used 
Coloring  Materials 

Manufacture  of  Glass  ^     .     .     .     . 

Careful  Preparation  of  Materials 
Preparation  of  the  Sand 
Mixing  the  Batch 
Fusing  and  Fining 
Glass  Furnaces 

Careful  Construction  of  Furnaces 
Fuels 

Pot  Furnaces 
Fire  Clay 

Manufacture  of  Pots 
Tank  Furnaces 
Calcar  Furnace 
Fusing  Process 
V  Fining  Process 

IV    Finishing  Processes 34 

Removing  Molten  Glass  from  the  Furnace 

Methods  of  Shaping  Gathered  Glass 

Glass-Blowing 

How  a  Glassblower  Works 

Pressing  Glass 

Pressed  Glass  Used  in  Imitations 

Molding 

Annealing 

Process  of  Annealing 

Varieties  of  Kilns 

Polishing 

Defects  in  Glass 

Differences  in  Glass 

V    Bottles  and  Other  Special  Forms  of 

Glass ...    47 

Bottle-Making 
Blown  Bottles 
Molded  Bottles 

The  Owens  Automatic  Bottle  Machine 
Glass  for  Insulation 
^  Bullet-Proof  and  Safety  Glass 

Colored  Glas» 


CONTENTS 


XI 


PART  II  —  CUT  GLASS  AND  TABLEWARE 


CHAPTER 

VI    Cut  Glass 


page 
53 


•' 


Characteristics 

Materials 

Process 

Designing  and  Cutting 

Tracing  the  Design 

Cutting  Wheels 

Expert  Knowledge  Required 

Roughing 

Smoothing 

Polishing 

Figured  Blank  Glass 

Acid  Polishing 

Glass-Cutting  Machines 

How  to  Judge  Values 

Differences  Between  English  and  American  Glass 

Cut  Rock  Crystal 

Genuine  Rock  Crystal 

Works  of  Art  Carved  from  Rock  Crystal 

VII    Engraved,  Etched,  and  Carved  Glass    .    66 

Methods  of  Decoration 

Engraving 

Etching 

Needle-Etching 

Plate-Etching 

Sand-Blast  Etching 

Frosting 

Carving 

Embossing 

Trailing 


VIII    Tableware       .     .     . 

Stemware 

Shaping  Stemware 

Variety  of  Shapes 

Stem  Variations 

Tumblers 

Sets  for  Many  Purposes 

Single  Articles 


71 


Xll 


CONTENTS 


CHAPTBR 

IX    Mirrors  and  Table  Reflectors 

Mirrors 

Amalgam  Mirrors 

Silvered  Mirrors 

Platinum  Mirrors 

Plateaux  or  Table  Reflectors 

Ancient  Mirrors 


PAGS 

79 


> 


X 


Design  in  Glassware 

Fundamentals  of  Design 

Importance  of   Shape 

Shapes  of  Cut  Glass  and  Blown  Glass  Articles 

Purpose  for  Which  Article  Is  to  be  Used 

Designs  for  Cut  Glass 

Standard  Cut  Glass  Patterns 

Engraved  Glass  Patterns 

Laws  of  Design 

Elements  of  Design 

Good  Design 

The  Use  of  Color  in  Design 


83 


CHAPTER 


PART  III  —  DECORATIVE  GLASS 
XI    Methods  of  Decoration 95 

Possibilities  of  Glass 

Colored  Decoration  of  Glass  Surfaces 

Gilding 

Gold  Resist 

Gold  Banding 

Gold-leaf 

Painting  and  Enameling 

Lacquering  or  Japanning 

Silver  Deposit  Glass 

Process  of  Manufacture  of  Silver  Deposit  Ware 

Sketching  the  Pattern 

Firing 

Electroplating 

Polishing 

Engraving  the  Silver  Deposit 

Original  Process 


XIII 


CONTENTS 


Meanmg  of  the  Term  "Art  Glass" 
Colored  Glass 
Flashed  Glass 

XII     Venetian  and  Bohemian  Glass 


xui 


PAGB 


107 


Beauty  of  Design  and  Coloring  in  Venetian  Glass 

Composition 

Curious  Shapes 

Process  of  Formation 

Filigree  Glass 

Cameo  Glass 

Mosaic  Glass 

Frosted  Glass 

Laticella  Glass 

Millefiori  Glass 

Coloring  of  Venetian  Glass 

Bohemian  Glass 

Methods  of  Ornamentation 

History  of  Bohemian  Glass 

Tiffany  Favrile  Glass 117 

Old  Industry  Revived 

Window  Glass 

Peacock  Glass 

Shapes 

Characteristic  Colors  of  Tiffany  Favrile  Glass 


!! 


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♦I 


XIV    Vases  and  Candlesticks 

Varieties 
Table  Vases 
Ornamental  Vases 
Glass  Candlesticks 


XV    Lamps  and  Lighting  Fixtures 

The  Lamp  Department 

Lamps 

Types  of  Oil  Lamps 

Adjustable  Lamps 

Lamp  Chimneys 

Lamp  Stands 

Lampshades 


121 


125 


XIV 


CBAPTBK 


CONTENTS 


Candlesticks  and  Candelabra 
Lanterns 

Lighting  Fixtures 
Indirect  Lighting 
Semi-Indirect  Lighting 
Daylight  Glass 
History  of  Lamps 


XVI 


Optical  Glass      .... 

Requirements  of  Optical  Glass 

Veins  or  Striae 

Furnaces  and  Crucibles 

Materials 

Manufacture 

Jena  Glass 

American  Optical  Glass 

Lens-Grinding 

Lenses  and  Prisms 

Laboratory  Glass 

Thermometers 

XVII    Windows  and  Window  Glass 


140 


.  151 


^ 


Kinds  of  Glass  Used  in  Windows 

Window   Glazing 

Double-Hung  Windows 

Casement  Windows 

French  Windows 

English  Casement  Windows 

Leaded  Lights 

Kinds  of  Glass  Used  in  Leaded  Lights 

History  of  Window  Glass 

Stained  Glass 

Enamel-Painted  Windows 

Opalescent  Windows 

Antique  Glass  Windows 

Antique  Glass 

Reproductions  of  Antique  Glass 

The  Making  of  Stained  Glass  Windows 

Silver  Stain 

Firing 

Glazing 

Effect  of  the  Finished  Window 

Stained  Glass  Design 


CONTENTS 


CBAPTBR 


XV 


PA<» 


PART  IV— THE  GLASS  INDUSTRY 

XVIII    History  of  Glass-Making 173 

V/onders  of  Glass-Making 

Glassmakers  of  Egypt 

Theban  Works  of  Art 

Glass  of  Other  Oriental  Countries 

Assyrian  Workmanship 

Persian  Glassware 

Characteristics  of  Grecian  Glass 

Roman  Glass 

Varieties  of  Glassware 

Glass  of  Pompeii  and  Herculaneum 

Varieties  of  Bottles 

Other  Glassware 

Venetian  Glass 

Murano  a  Famous  Glass  Center 

Development  of  Art  in  Other  Countries 

Spanish  Glass 

Bohemian  Glass 

Other  Varieties 

Early  Art  in  France 

English  Glass 

Growth  of  the  Glass  Industry  in  England 

Characteristics  of  English  Glass 


XIX    The   Glass    Industry   in   the   United 
States     

Early  Experiments 
Pioneer  Glass-Making  Concerns 
Growth  of  the  Industry 
Pressed  Glassware 
Pressed  Lime  Glass 
Invasion  of  Foreign  Markets 
The  Owens  Bottle  Machine 
Improvements  in  Furnaces 
In  the  Middle  West 

XX    Suggestions  to  Salespeople    .... 

Qualifications  for  Selling  Glass 
Manufacture 


192 


199 


, 


3CV1 

CBAPTBK 


XXI 


CONTENTS 

PAGB 

Other  Points  of  Importance  to  Customers 

Suitability 

Arrangement 

Care 

Cleaning 

Things  to  be  Avoided 

Classification  of  Stock  of  a  Typical 
Glassware  Department 206 


Appendix    . 

Books  for  Reference 


2X1 


i 


LIST  OF  ILLUSTRATIONS 


Forming  the  Stem  of  a  Goblet Frontispiece 

Finished  Goblet  Ready  for  Annealing    ....  Frontispiece 

FIGURE  FACING   PAGE 

1.  Open  Pot  for  Glass-Melting (on  page)      26 

2.  Covered  Pot  for  Glass-Melting (on  page)      26 

3.  Diagram  of  a  Furnace  with  a  Horseshoe  Flame    .    .    . 

(on  page)      30 

4.  Rolling  Glass  on  Marver 36 

5.  The  Evolution  of  a  Tumbler (on  page)  37 

6.  Cutting   Glass S6 

7.  Cut  Glass  Goblet  in  Poppy  Design 62 

8.  Patterns  in   Miter  Cutting 86 

9.  Examples  of  Venetian  Glassware 112 

10.  Example  of  Bohemian  Engraved  Glass 114 

11.  Leaded  Glass 156 

12.  Stained  Glass  Window 170 

13.  Examples  of   Roman   Molded   Glass 178 

14.  Ancient  Venetian   Glass   Furnace 182 

15.  Ancient  Glassmakers*  Tools (on  page)  183 


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GLASS  AND  GLASSWARE 


Chapter  I 

THE  GLASSWARE  DEPARTMENT 

Effective  Display 

One  of  the  most  beautiful  and  effective  displays  of 
the  modem  store  is  found  in  the  Glassware  Depart- 
ment. It  is  sometimes  situated  where  the  natural  light 
is  strong ;  but  more  often  it  is  lighted  artificially  with  an 
arrangement  of  mirrors  and  reflectors  to  give  the  most 
brilliant  and  dazzling  effect. 

Glassware  is  placed  on  glass  shelves  —  often  mir- 
rors with  mirror  backgrounds  —  on  polished  tables,  or 
on  velvet  or  felt.  Sets  are  arranged  on  mirror  pla- 
teaux which  give  them  a  double  reflection. 

Colored  glass  is  grouped  harmoniously ;  a  few  pieces 
are  often  introduced  among  the  crystal  to  heighten 
the  beauty  of  each  by  contrast.    The  decorations  in 


2  GLASSWARE  DEPARTMENT 

gold,  silver,  and  enamel  are  brilliant  and  glistening  and 
add  to  the  effect  of  splendor. 

Divisions  of  the  Glassware  Department 

There  are  usually  three  general  divisions  of  the 
Glassware  Department: 

1.  Tableware 

2.  Toilet  sets 

3.  Decorative  or  art  glass 

Sometimes  a  division  is  made  between  the  domestic 
and  the  imported  glass;  but  the  American  glass  is  so 
excellent  in  quality  that  there  is  no  need  for  such  a 
distinction. 

Glass  is  also  divided  according  to  its  composition, 
into: 

Flint,  lead,  or  crystal  glass 
Lime  or  lime-crystal  glass 
Common  or  bottle-glass 

Manufacturers  are  known  as  flint  or  lime  manufac- 
turers, according  to  the  kind  of  glass  they  produce. 

Cut  glass  is  made  of  lead  or  flint  glass  and  is  some- 
times called  cut  rock  crystal;  pressed  or  molded  glass 
is  lime-crystal;  and  the  cheaper  grades  may  be  bottle- 
glass. 

Glass  is  also  referred  to  commercially  as  American, 


INTRODUCTORY  3 

Belgian,  Bohemian,  Swedish,  French,  or  English,  in- 
dicating the  country  in  which  it  was  made;  and  in 
other  cases  it  may  be  referred  to  by  the  name  of  the 
manufacturer. 

Characteristics  of  Glass 

Glass  is  one  of  the  most  valuable  of  all  manufac- 
tured materials.  It  has  the  three  most  essential  quali- 
ties : 

Utility 

Durability 

Beauty 

Utility 

The  usefulness  of  glass  is  primarily  due  to  its  great 
adaptability.  As  a  container  of  food  it  is  almost  per- 
fect, as  it  can  be  attacked  by  only  one  acid  and  that 
acid  is  not  found  in  food.  It  is,  however,  slightly 
affected  by  strong  alkalies. 

Because  of  its  smooth  surface  it  can  be  kept  clean 
and  will  not  retain  odors ;  and  thus  it  makes  the  best 
possible  container  for  liquids,  medicines,  and  nearly 
all  chemicals. 

Because  of  its  transparency  it  is  the  best  material 
for  windows,  lamp  chimneys,  shades,  and  all  illumi- 
nating fixtures. 

Its  use  in  photography,  astronomy,  and  all  the  phys- 


h- 


[•  ^ 


4  GLASSWARE  DEPARTMENT 

ical  sciences  is  unequaled,  and  it  is  the  one  material 
which  can  preserve  and  aid  the  sight. 

Durability 

The  durability  of  glass  is  not  generally  realized.  It 
is  brittle,  of  course,  and  may  be  fractured  by  a  blow 
or  by  too  sudden  expansion  or  contraction  caused  by 
sudden  applications  of  heat  or  cold.  On  the  other 
hand,  ordinary  usage  does  not  wear  it  out  and  the 
atmosphere  does  not  disintegrate  it. 

Its  durability  is  largely  dependent  upon  careful  an- 
nealing, which  is  one  of  the  finishing  processes. 

Beauty 

The  transparency  and  the  refraction  of  light  by  col- 
orless  glass  makes  it  beautiful.  This  beauty  may  be 
increased  by  cutting,  polishing,  and  other  modes  of 
decoration  and  by  the  addition  of  color.  The  dazzling 
beauty  of  artistic  glass  almost  equals  that  of  perfect 
gems. 


Part  I— Manufacture  of  Glass 


Chapter  II 

GLASS  MATERIALS 

Nature  and  Composition 

Glass  is  an  artificial  substance  of  mineral  composi- 
tion. It  has  some  of  the  characteristics  of  metals  and 
some  of  those  of  the  non-metallic  minerals.  It  re- 
sembles metals  in  that  it  may  be  molded  or  drawn  out 
into  thin  threads  or  tubes  when  heated  to  a  certain 
temperature ;  but  it  is  far  more  brittle.  When  heated, 
glass  becomes  viscous;  that  is,  in  a  condition  between 
that  of  a  liquid  and  that  of  a  true  solid ;  when  cool,  the 
materials  of  which  it  is  composed  are  held  together  in 
solution  but  not  actually  united. 

Under  ordinary  conditions  glass  is  transparent, 
though  it  may  readily  be  made  so  that  one  cannot  see 
through  it.  It  might  easily  be  mistaken  for  those  nat- 
ural mineral  formations  which  we  call  precious  stones, 
except  that  it  never  crystallizes. 


6  GLASSWARE  DEPARTMENT 

Difference  Between  Precious  Stones  and  Glass 

All  transparent  minerals,  and  many  which  are  not 
transparent,  have  a  crystalline  formation  —  that  is,  the 
tiny  particles  of  which  they  are  composed  are  grouped 
in  regular  geometrical  figures.  These  figures  may  be 
too  small  to  be  seen  without  a  microscope ;  but  they  are 
always  there,  and  it  is  the  reflection  of  light  from  these 
tiny  particles  that  makes  polished  stones  used  in  jew- 
elry more  beautiful  than  glass.  Glass  has  none  of 
these  tiny  crystals. 

Materials  of  Which  Glass  Is  Composed 
Glass  contains: 

Sand  or  silica 

Lime 

Lead  or  flint 

Soda  or  potash 

It  may  also  contain  metallic  oxides  for  coloring  mat- 
ter and  frequently  other  metals,  such  as  aluminum, 
iron,  zinc,  magnesium,  barium,  borax,  arsenic,  and 
antimony. 

Glass  containing  a  number  of  different  materials 
melts  at  a  lower  temperature,  but  is  less  perfect  in 
structure,  than  that  composed  of  pure  silica,  lime,  and 
soda;  or  silica,  lead,  and  potash.  These  materials 
mixed  together  form  what  is  called  the  *'batch,"  that 


GLASS  MATERIALS  ^ 

is,  the  mixture  which,  when  sufficient  heat  is  applied, 
becomes  glass. 

Sand 

As  clay  is  the  main  element  in  all  pottery,  so  is  sand 
the  essential  material  in  the  making  of  glass.  No 
glass  can  be  made  without  it.  It  contributes  toughness 
and  strength  to  the  batch  and  the  viscosity  which 
makes  it  possible  to  shape  the  molten  glass  into  proper 

form. 

In  an  elementary  class  in  chemistry,  experiments  in 
which  acids  and  alkalies  combine  are  often  shown 
early  in  the  course.  The  instructor  perhaps  pours  hy- 
drochloric acid  into  a  dish  containing  soda,  and  the 
students  observe  the  violent  boiling  and  bubbling  that 
follows.  This  is  known  as  a  chemical  reaction. 
After  things  quiet  down  and  evaporation  takes  place, 
the  dish  contains  a  substance  neither  acid  nor  soda,  but 
a  neutral  compound  formed  by  the  union  of  the  chlorin 
of  the  acid  with  the  sodium  of  the  soda,  which  proves 
to  be  sodium  chlorid,  or  common  salt. 

A  similar  happening  takes  place  in  the  making  of 
glass.  An  acid  is  generally  thought  of  as  a  liquid 
with  a  sour  taste  and  pungent  odor,  and  it  may  seem 
an  absurd  statement  to  say  that  sand  is  an  acid.  Nev- 
ertheless from  a  chemical  standpoint  the  statement  is 
true.     When  the  sand  is  mixed  with  the  soda  and  lime 


8 


GLASSWARE  DEPARTMENT 


the  high  temperature  of  the  furnace  is  all  that  is 
needed  to  bring  about  just  such  a  reaction  as  occurs 
when  hydrochloric  acid  and  soda  are  brought  together. 
The  resulting  compound,  glass,  is  therefore  a  neutral 
salt  (silicate  of  sodium  and  calcium),  although  its 
properties  differ  greatly  from  other  salts. 

Occurrence  of  Sand 

Sand  in  one  of  its  various  forms  exists  everywhere. 
It  is  formed  by  the  wearing  away  of  rocks  by  wind, 
rain,  snow,  and  other  forces  of  nature.  It  is  finally 
deposited  in  a  pure  state  in  sea,  river,  or  lake  beds, 
and  in  a  less  pure  state  in  the  sandy  soils  of  certain 
districts.  What  is  called  "  sand  "  may  be  almost  any- 
thing from  nearly  pure  silica  (sand  that  is  99.9  per 
cent  pure)  down  to  clay  marls,  a  crumbling  deposit 
consisting  chiefly  of  clay  mixed  with  limestone,  which 
contains  very  little  silica. 

Quality  of  Sand  Depends  on  Constituents 

The  quality  of  sand  is  largely  determined  by  the 
amount  of  other  substances  it  contains,  such  as  com- 
pounds of  iron,  lime,  aluminum,  and  magnesium.  If 
pure  it  is  perfectly  white  and  does  not  effervesce  or 
change  color  when  treated  with  an  acid.  It  is  insolu- 
ble in  all  acids  except  hydrofluoric. 

The  value  of  sand  is  largely  determined  by  the 


GLASS  MATERIALS  9 

amount  of  iron  it  contains,  because  iron  gives  glass  a 
greenish-yellow  or  clouded  appearance.  As  nearly  all 
sand  contains  some  iron,  cobalt  or  manganese  is  usually 
added  to  neutralize  the  undesirable  color. 

The  sand  used  in  making  the  best  grades  of  glass- 
ware must  be  free  from  impurities,  fine,  and  of  uni- 
form quality.  If  the  sand  is  too  coarse  it  will  not 
fuse  quickly,  and  if  it  is  too  fine  it  will  melt  too  rapidly. 

Sand  Beds 

The  most  desirable  sand  is  usually  found  on  the 
seashore  or  in  the  beds  of  rivers  or  lakes,  where  the 
grains  are  ground  to  a  uniform  size  and  shape  by  the 
constant  friction  of  the  water. 

Two  famous  sources  are  the  Forest  of  Fontainebleau 
near  Paris  and  Alum  Bay  in  the  Isle  of  Wight. 
Epinal,  Belgium,  has  sand  of  almost  equally  pure  com- 
position.    English  sands  are  not  of  such  high  quality. 

Most  of  the  sand  in  the  United  States  is  tinged  with 
yellow  or  gray.  Practically  every  state  in  the  Union 
contains  sand  fit  for  glass.  The  most  important  de- 
posits in  the  country,  however,  are  located  in  West 
Virginia,  Massachusetts,  Pennsylvania,  and  Illinois. 
Sand  from  the  Berkshires  in  Massachusetts  is  prac- 
tically free  from  iron,  and  that  from  Pennsylvania 
contains  less  than  .01  per  cent.  The  finest  quality  is 
found  in  West  Virginia.    The  mountains  there  con- 


'  JjL^K. 


,N 


lO 


GLASSWARE  DEPARTMENT 


tain  mines  of  sand  said  to  be  as  pure  as  that  from 
Fontainebleau. 

Sandstone 

Pure  sand  may  be  obtained  by  crushing  sandstone, 
but  the  grains  thus  obtained  are  not  likely  to  be  so 
uniform  in  size  as  those  from  a  sand  bed,  and  the 
necessary  grinding  makes  its  preparation  more  expen- 
sive and  tedious. 

Quartz 

Quartz  is  crystallized  sand.  It  appears  in  nature  as 
rock  crystal,  a  transparent  and  colorless  variety,  and 
also  in  a  number  of  semiprecious  stones,  such  as  the 
amethyst  and  false  topaz.  These  forms  of  silica  might 
be  crushed  and  used  for  glass,  but  their  hardness  and 
intrinsic  value  make  them  too  expensive  for  such  use. 
Low-grade  quartz  is  sometimes  used. 

Flint 

Flint  is  a  form  of  quartz  containing  lead  and  potash, 
which  appears  in  certain  localities  in  the  form  of  boul- 
ders or  large  pebbles.  It  was  used  very  generally  by 
the  early  English  glassmakers.  The  name  "  flint  **  is 
still  applied  to  a  kind  of  glass  that  is  soft,  brilliant,  and 
suitable  for  cutting.  Now,  however,  this  kind  of  glass 
is  usually  made  from  oxide  of  lead  and  is  more  com- 


GLASS  MATERIALS 


II 


monly  referred  to  as  crystal  or  lead  glass.  In  France 
these  flint  pebbles  are  still  gathered  on  the  sea  and 
river  shores  and  carried  by  the  peasants  to  the  glass- 
makers. 

Flint  must  be  finely  ground  before  being  used,  and 
as  this  is  an  expensive  and  tedious  process,  it  is  suit- 
able only  for  the  best  grade  of  glassware. 

The  various  trade  terms  in  use  are  apt  to  be  some- 
what confusing. 
.  "  Lead  flint  '*  glass  contains : 

Sand  or  silica 

Oxide  of  lead 

Potash  or  pearlash  (a  special  form  of  potash) 

Saltpeter 

"  Lime  flint  "  glass  contains : 

Sand 

Lime 

Bicarbonate  of  soda 

Saltpeter 

"  Strass  "  is  a  flint  glass  with  a  large  amount  of 
lead ;  it  is  used  for  making  artificial  gems. 

Kelp  or  Seaweed 

Seaweed  and  other  forms  of  plant  life  were  at  one 
time  another  source  of  silica,  as  the  stalks  of  many 
sea  plants,  such  as  kelp,  are  stiffened  with  it.     Modern 


12 


GLASSWARE  DEPARTMENT 


invention,  however,  makes  it  more  profitable  to  utilize 
such  sea  plants  by  extracting  the  potash  and  soda  they 
contain  rather  than  the  silica,  which  may  be  obtained 
by  less  expensive  methods. 

Alkalies 

Next  in  importance  to  sand  or  silica  among  the  con- 
stituents of  glass  are  the  alkalies,  potash  and  soda. 
They  are  necessary  in  order  to  make  the  other  materi- 
als melt  and  combine  and  are  called  "  fluxes."  Modern 
glassmakers  obtain  them  from  natural  deposits  and 
prepare  them  in  special  factories.  Both  are  found  in 
nature  in  various  combinations:  chlorids,  sulphates, 
carbonates,  and  nitrates.  The  forms  generally  used, 
carbonates  and  sulphates,  are  the  most  desirable  from 
the  glassmaker's  point  of  view,  since  they  are  the  pur- 
est and  of  the  most  uniform  composition. 

Potash 

Pearlash  (potassium  carbonate)  is  the  form  of  pot- 
ash most  commonly  used.  Crude  pearlash  is  obtained 
from  ashes  as  a  by-product  of  the  beet-sugar  industry 
and  is  used  for  inexpensive  glass.  Saltpeter  (potas- 
sium nitrate)  is  another  form  valuable  for  its  oxygen 
and  alkali.  Ancient  glass  contained  potash  made  from 
seaweed  or  kelp,  but  this  was  inferior  to  modem  pot- 
ash because  of  its  impurities. 


.-4 

1 


GLASS  MATERIALS 


13 


Natural  deposits  of  potash  were  discovered  in  the 
mines  of  Strassfurth  near  the  River  Elbe  in  Germany, 
and  almost  the  entire  world  became  dependent  on 
them.  When  war  conditions  shut  off  the  supply,  the 
potash  situation  became  serious.  Fortunately  for  the 
American  industry,  local  fields  of  kelp  were  discovered, 
which  brought  relief  for  the  time,  but  Germany  is  still 
the  great  source  of  the  world's  supply. 

American  Potash 

A  potash  mine  is  being  worked  in  New  England, 
where  a  shaft  i,ooo  feet  deep  has  been  sunk.  Night 
and  day  shifts  are  working  the  deposits.  It  has  been 
known  for  a  long  time  that  there  are  considerable  pot- 
ash deposits  in  the  vicinity,  but  they  were  not  mined 
to  any  extent  until  the  cutting  off  of  the  European 
supply  made .  the  mining  of  potash  in  this  country 
worth  while. 

Large  amounts  of  the  compounds  of  this  element 
are  present  in  the  vast  beds  of  kelp  floating  on  the 
waves  of  the  Pacific  near  the  western  coast.  Each 
year  the  waters  of  the  Pacific  coast  yield  a  crop  from 
which  potash  salts  possessing  a  normal  value  of  more 
than  $90,000,000  can  be  readily  extracted  for  use  in 
agriculture  and  the  arts.  Not  only  are  there  inex- 
haustible supplies  in  the  waters  of  the  Pacific,  but  also 
remarkable  deposits  in  the  arid  waste  about  Searles 


i 


14 


GLASSWARE  DEPARTMENT 


Lake  in  California,  and  in  Utah.     Beds  of  kelp  have 
also  been  discovered  in  the  Philippines. 

Soda 

The  general  use  of  soda  as  a  flux  is  a  more  recent 
development  than  the  use  of  potash,  though  much  of 
the  glass  of  ancient  times  was  soda  glass.  As  with 
potash,  it  was  first  obtained  from  the  burning  of 
seaweed. 

Soda-Ash 

Soda-ash  (sodium  carbonate)  is  the  purest  form 
and  is  used  in  the  better  glass  works.  It  is  made  by 
treating  the  natural  soda  deposits  with  certain  chem- 
icals. 

Salt-Cake 

Salt-cake  (sodium  sulphate)  is  a  cruder  form  used 
in  making  bottles  and  the  heavier  glassware.  It  is 
produced  in  the  same  manner  as  soda-ash. 

Chile  Saltpeter 

Chile  saltpeter  (sodium  nitrate)  is  used  in  the  crude 
state  or  refined  for  the  better  ware.  The  nitrates  of 
both  soda  and  potash  are  valuable  for  the  alkalies  they 
contain,  but  more  particularly  for  the  oxygen  which 
aids  in  freeing  the  batch  from  bubbles. 


GLASS  MATERIALS 


IS 


Lead  and  Lime 


The  third  necessary  ingredient  of  glass  is  either  lead 
or  lime.  Lead  is  used  for  the  best  cut  glass,  because 
of  the  brilliancy,  resonance,  and  weight  which  it  gives. 
It  also  lowers  the  melting  point  of  the  batch. 

Forms  of  Lead  Used 

Lead  oxide  is  an  expensive  material  for  glass- 
making.  Red  lead,  the  form  generally  used,  is  of  a 
bright  red  color.  It  is  preferable  to  other  oxides  be- 
cause it  is  easily  decomposed  by  heat.  It  is  made  by 
roasting  metallic  lead  in  furnaces  to  eliminate  the 
impurities  present,  such  as  silver,  iron,  and  silica. 
Red  lead  is  very  poisonous  and  the  workmen  in  flint 
glass  factories  have  to  wear  respirators  to  keep  them 
from  inhaling  lead  dust  while  they  are  preparing  it. 
In  good  factories  perfect  cleanliness  is  also  insisted 
upon  so  that  the  lead  may  not  poison  the  workmen's 
food. 

Kinds  of  Lime  Used 

Lime  (calcium  oxide)  is  a  much  less  costly  mate- 
rial. It  makes  a  harder  glass  than  lead,  and  for  this 
reason  lime  glass  is  not  suitable  for  cutting.  It  may 
be  used,  however,  for  all  kinds  of  pressed  ware  and 
for  many  varieties  of  art  glass  where  lightness  and 
delicacy  are  desired.     Lime  adds  to  the  viscosity  of 


t 

< 


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GLASSWARE  DEPARTMENT 


the  molten  glass,  and  so  increases  the  toughness  and 
serviceability  of  the  finished  product.  If  used  in  ex- 
cess, it  gives  the  glass  a  milk-white  color. 

Lime  is  found  in  many  parts  of  the  world,  appear- 
ing as : 

Limestone  rock 

Chalk  (calcium  carbonate) 

Chalk  is  a  soft,  brittle  rock  which  can  be  easily 
ground  into  a  fine  powder.  It  is  often  mixed  with 
iron,  flint,  and  magnesia,  which  impair  its  quality. 

Gypsum  (calcium  sulphate)  is  a  form  of  lime  less 
pure  than  limestone,  sometimes  used  in  glass-making. 

Other  Materials  Used 
Other  materials  added  for  special  purposes  are : 

Aluminum 

Arsenic 

Barium 

Borax 

Magnesia 

Zinc 

Aluminum  is  found  In  small  quantities  in  nearly  all 
glass,  but  a  larger  percentage  is  used  in  opal  or  optical 
glass. 

Arsenic  acts  as  a  flux  and  neutralizes  certain  objec- 
tionable colors. 


GLASS  MATERIALS 


17 


Barium  replaces  lead  for  some  purposes  of  glass- 
making.     It  is  an  expensive  material. 

Borax  adds  to  the  density  and  brilliancy  of  glass. 

Magnesia  is  similar  to  lime,  for  which  it  is  some- 
times substituted. 

Zinc  contributes  some  of  the  same  qualities  that 
soda  and  potash  do.     It  is  used  in  special  optical  glass. 


i|  i 


Coloring  Materials 

Transparent  colored  glasses  are  made  by  simply 
adding  coloring  components  in  relatively  small  quanti- 
ties, to  the  clear  glass  batch.  These  are  usually  me- 
tallic oxides:  copper  or  cobalt  for  blues;  chrome  or 
iron  for  greens;  silver  or  uranium  for  yellows;  and 
gold  chlorid  or  seleniun  for  ruby.  The  deep  amber 
used  for  bottles  is  made  by  adding  carbon  with  sul- 
phur in  some  form;  this  is  generally  coal  dust,  but 
any  of  the  grains  wheat,  oats,  barley,  or  even  saw- 
dust, will  make  a  rich  amber  color. 

The  opaque  and  semiopaque  glasses  require  the  same 
foundation  mixture,  but  other  materials  in  larger  pro- 
portions are  needed  to  insure  sufficient  opacity.  Some 
of  these  other  materials  do  not  become  chemically 
components  of  the  glass,  but  remain  in  mechanical  sus- 
pension only,  i.e.,  floating  in  fine  particles,  and  tend 
to  destroy  the  uniformity  and  strength  of  the  glass. 


I  ' 


^ 


H  I 


i8 


GLASSWARE  DEPARTMENT 


Others  exert  a  destructive  action  on  the  pots  or  cruci- 
bles holding  the  batch. 

These  are  some  of  the  reasons  why  opaque  glass 
has  not  been  in  more  general  use  for  the  manufacture 
of  hollow  wares,  but  recent  progress  has  been  made 
in  eliminating  or  neutraHzing  the  injurious  effects  of 
the  ingredients  referred  to,  and  producing  a  material 
which  will  stand  rough  usage.  Opaque  glass  is  there- 
fore now  invading  a  field  which  hitherto  has  belonged 
exclusively  to  the  potter. 

The  translucent  lighting  glass  now  so  much  in 
favor,  because  of  its  superiority,  is  crystal  glass  to 
to  which  has  been  added  opacifying  components, 
the  most  essential  being  oxide  of  aluminum. 

Lead  and  bismuth  are  the  only  metallic  oxides  which 
can  be  added  to  silica  and  alkali  without  discoloring 
the  batch.  Even  an  excess  of  lead  gives  a  yellowish 
tinge. 

Owing  to  the  presence  of  metallic  substances  in 
nearly  all  sand  used  for  glass-making,  colored  glass 
has  always  been  more  common  than  that  which  is  clear 
and  colorless. 

Color  which  is  muddy  and  dull,  such  as  the  green  or 
the  brown  tinge  of  common  bottle-glass,  is  due  to  the 
use  of  low-grade  materials;  but  the  colors  which  may 
be  produced  by  the  introduction  of  carefully  prepared 
metallic  oxides,  which  are  used  with  a  scientific  knowl- 


GLASS  MATERIALS 


19 


edge  of  their  effect  on  the  silica  and  alkali  of  the 
batch,  add  the  final  touch  of  beauty  to  decorative  glass 
which  brings  it  into  the  region  of  the  fine  arts.  The 
further  discussion  of  color  therefore  belongs  in  the 
section  devoted  to  art  glass. 


i 


/ 


Chapter  III 

MANUFACTURE  OF  GLASS 

Careful  Preparation  of  Materials 

The  quality  and  the  appearance  of  finished  glass- 
ware depend  upon  the  purity  and  fineness  of  the  ma- 
terials of  which  it  is  made,  and  the  proper  propor- 
tions of  each  in  the  mixture  which  forms  the  batch. 
Each  material  must  also  be  as  free  as  possible  from 
water,  as  moisture  hinders  the  melting  process. 

Preparation  of  the  Sand 

Sand  for  the  manufacture  of  glass  is  first  carefully 
examined  under  the  microscope  and  analyzed  by  chem- 
ical tests  for  purity.  It  is  then  emptied  into  recepta- 
cles containing  a  large  quantity  of  clean,  pure  water, 
moved  about  vigorously,  and  allowed  to  settle.  As  it 
is  heavier  than  water  it  naturally  falls  to  the  bottom, 
while  the  particles  of  foreign  matter  which  float  upon 
the  top  are  drawn  off  with  the  water. 

The  sand  is  next  burned  to  remove  the  moisture  and 
to  destroy  any  vegetable  matter  which  has  not  been 
taken  out.     For  this  process  it  is  placed  on  the  bed 

20 


MANUFACTURE  OF  GLASS 


21 


'of  a  moving  oven  which  travels  continuously  through 
flames. 

From  the  oven  bed  it  is  dropped  into  a  vault  through 
a  series  of  sieves  covered  with  fine  copper  gauze. 
This  sifting  process  not  only  removes  impurities  but 
also  aids  in  procuring  a  sand  with  grains  of  uniform 
size. 

The  other  materials  are  usually  refined  and  prepared 
before  they  reach  the  glass  manufacturer. 

Mixing  the  Batch 

The  mixing  of  glass  materials  must  be  done  with 
scientific  accuracy,  as  an  excess  or  deficiency  of  any 
one  of  them  affects  the  appearance  and  quality  of  the 
finished  product.  Too  much  sand  keeps  the  batch 
from  melting,  and  too  little  potash  or  soda  has  the 
same  result.  Too  much  lime  or  lead  affects  the  color 
and  quality.  All  coloring  compounds  must  be  used 
with  a  knowledge  of  their  chemical  reactions  in  order 
to  produce  the  proper  effect. 

Each  formula  must  therefore  be  prepared  by  a 
trained  chemist,  and  every  ingredient  carefully 
weighed.  The  formulas  for  certain  kinds  of  glass 
are  secret,  and  even  the  workmen  are  kept  in  ignorance 
of  them  lest  they  should  disclose  the  processes  to  a 
competing  manufacturer.  For  small  batches  the 
weighing  and  mixing  are  done  by  hand,  but  for  larger 


iii 


.*  ! 


f     1 


22 


GLASSWARE  DEPARTMENT 


quantities  by  machinery.  In  the  weighing  process 
only  the  ends  of  the  scale  beam  may  be  seen  by  the 
workmen,  the  exact  proportions  being  known  only  to 
a  few  members  of  the  concern. 

After  weighing,  the  materials  are  all  collected  in  an 
"assembly  box"  and  dumped  into  a  hopper,  which 
empties  its  contents  into  the  mixing  machine.  This 
machine  rotates  in  various  directions  while  revolving 
steel  arms  within  the  mixing  chamber  stir  the  contents. 
Samples  of  the  batch  are  taken  out  and  examined. 
When  the  sample  shows  that  the  whole  mass  is  uni- 
form in  color  and  texture,  the  "  cullet "  or  "  frit "  is 
added.  This  is  a  special  mixture  of  materials  in  a 
pulverized  and  half -molten  state  which  hastens  the 
process  of  melting  and  fusion  for  which  the  batch  is 
now  ready. 

Fusing  and  Fining 

The  fusing  of  the  materials  into  a  uniform  molten 
liquid  out  of  which  glass  articles  may  be  formed  is  a 
most  interesting  process.  "* 

After  the  fusing  the  next  step  in  the  manufacture 
is  fining.  By  means  of  intense  heat  and  some  material 
containing  oxygen,  impurities  and  gas  bubbles  are  re- 
moved. Both  of  these  important  processes  are  de- 
scribed in  greater  detail  in  the  latter  part  of  the  chap- 
ter.    Both  take  place  in  glass  furnaces. 


MANUFACTURE  OF  GLASS  23 

Glass  Furnaces 

Three  kinds  of  furnaces  are  needed  in  a  glass  fac- 
tory: 

1.  The  working  furnace,  either: 

(a)  Pot  or  crucible  furnaces,  or 

(b)  Tank  furnaces 

2.  The  calcar  furnace  for  making  frits 

3.  The  annealing  oven 

The  first  two  kinds  are  described  in  this  chapter,  the 
third  in  Chapter  IV. 

Careful  Construction  of  Furnaces 

Furnaces  for  making  glass  must  be  built  with  a  view 
to  durability,  regularity,  and  intensity  of  heat,  and 
also  economy  of  fuel.  Since  they  must  resist  a  tem- 
perature of  between  1,800°  and  2,700°  R,  glass  fur- 
naces are  constructed  of  fire-proof  bricks  made  of  an 
infusible  clay  mixed  with  cement  obtained  from  the 
pulverization  of  old  pots  —  the  containers  for  molten 
glass.  The  fire  of  the  furnace  never  goes  out  imtil 
the  furnace  wears  out  after  one  or  two  years  of 
service. 

Glass  furnaces  have  much  in  common  with  pottery 
furnaces  except  that  the  heat  of  the  glass  furnace  is 
more  constant.  Upon  the  regularity  of  its  heat  de- 
pends the  safety  of  the  crucibles  as  well  as  the  quality 


I" 


*l  1 


24 


GLASSWARE  DEPARTMENT 


^,...1M«..#*****^ 


j^^^XstA^ 


of  the  glass  they  contain.  Sudden  variations  of  tem- 
perature tend  to  crack  the  crucibles  and  irregular  cool- 
ing "  striates  "  or  streaks  the  glass. 

The  furnace  must  be  constructed  so  as  to  resist 
great  heat  and  avoid  drafts,  and  must  be  very  durable. 
The  fuel  must  be  as  free  as  possible  from  impurities, 
and  the  degree  of  heat  applied  and  the  duration  of  the 
fusing  process  must  be  carefully  regulated  or  the  entire 
batch  may  be  wasted. 

Fuels 

The  kind  and  the  quality  of  the  fuel  used  in  a  glass 

furnace  is  of  importance.     Wood  was  naturally  the 

'  /i  first  fuel  to  be  used.     It  made  a  clean  heat  but  one  of 

V^   slow  and  uncertain  temperature,  varying  with  the  kind 

I        of  wood  used  and  with  its  wet  or  dry  condition.     The 

old  glassmaker,  like  the  old  potter,  knew  the  value  of 

the  various  kinds  of  woods  for  his  purpose  and  chose 

them  accordingly. 

The  use  of  coal  necessitates  covering  the  pots  in 
which  the  glass  is  melted  to  prevent  the  soot  and  sul- 
phur from  coming  in  contact  with  the  glass  and  thus 
filling  it  with  small  particles  of  harmful  matter  as  well 
as  affecting  its  color.  This  was  a  constant  annoyance 
to  the  glassmaker. 

The  introduction  of  the  hooded  pot  necessitated  the 
addition  of  more  fluxing  material  or  of  more  heat  to 


MANUFACTURE  OF  GLASS 


2S 


make  the  batch  melt,  because  the  hood  prevented  the 
flame  from  touching  the  batch  as  in  the  case  of  open 
pots.  The  discovery  of  gas  as  a  fuel  solved  the  prob- 
lem for  this  country. 

The  glassmaker  of  modem  times  owes  much  to  the 
discovery  of  natural  gas  as  a  fuel.  It  makes  a  smoke- 
less flame  and  has  scarcely  any  impurities.  It  pro- 
vides a  uniform  heat  and  there  is  no  discoloration  from 
smoke.  It  gives  no  trouble  through  the  accumulation 
of  ashes  or  dirt 

The  introduction  of  gas  as  a  fuel  has  revolutionized 
the  whole  glass-making  industry.  In  the  United 
States  both  gas  and  petroleum  are  used.  Even  for  pot 
furnaces  gas  is  used ;  in  tank  furnaces  it  is  indispensa- 
ble. Natural  gas  is  employed  wherever  it  is  obtain- 
able. Where  there  is  no  natural  gas,  artificial  gas  is 
made  from  other  fuels. 


M 


Pot  Furnaces 

The  pot  furnace  is  circular,  with  a  chimney  in  the 
middle  through  which  the  smoke,  flame,  and  heated 
air  escape.  At  the  base  of  this  enormous  chimney  is 
a  central  fire,  and  fire  bars  occupy  the  middle  of  the 
furnace  floor.  On  the  sides  of  the  furnace  are  recesses 
in  which  the  workmen  stand ;  and  on  the  inner  sides  of 
these  recesses  are  openings  into  the  pots  or  crucibles 


'  1 


1 .1 


26 


GLASSWARE  DEPARTMENT 


MANUFACTURE  OF  GLASS 


27 


which  are  placed  opposite  on  a  clay  stand  or  shelf 
around  the  circumference  of  the  furnace. 

Each  crucible  has  one  small  opening  only,  near  the 
top,  in  the  shape  of  a  neck  projecting  out  through  the 
furnace  wall.  Through  this  opening  the  batch  is  poured 
into  the  crucible ;  during  the  melting  it  is  tightly  sealed 
so  as  to  be  practically  air-tight,  and  no  direct  flame, 
smoke,  or  heat  gets  to  the  fusing  glass.     Because  of 


Figure  i.    Open  Pot  for 
Glass-Melting 


Figure  2.    Covered  Pot  for 
Glass-Melting 


this  protection  from  outside  influences  it  is  possible  to 
make  glass  of  greater  luster  and  better  color  than  can 
be  made  otherwise  in  the  present  state  of  the  art.  The 
word  "color "  is  here  used  in  its  technical  sense  as 
applied  to  crystal  glass.  When  a  glassmaker  says  his 
glass  is  of  good  color,  he  really  means  that  it  is  with- 
out color,  or  as  nearly  so  as  he  can  get  it. 

A  furnace  is  described  as  having  so  many  "  pots,'* 
the  number  of  these  indicating  its  size.  The  pots  vary 
in  shape  and  capacity.  They  may  be  round,  oval,  or 
rectangular,  from  18  inches  to  3  feet  in  height,  and 


with  open,  or  *'  hooded  "  or  domed  tops.  They  may 
hold  a  few  pounds  (monkeys),  or  several  tons  of 
molten  glass.  Figure  i  shows  an  open  pot;  Figure  a 
a  covered  one. 

Pots  last  only  a  few  weeks  though  it  takes  months 
to  make  them.  While  in  use  they  require  the  most 
careful  attention,  as  the  intense  heat  widens  even  the 
smallest  crack  and  soon  breaks  the  pot.  This  means 
the  loss  of  the  entire  batch  of  glass. 

The  process  of  making  glass  in  a  pot  furnace  may  be 
more  carefully  regulated  than  is  the  case  with  other 
processes,  because  the  glass  is  in  comparatively  small 
quantities  and  the  molten  mass  may  be  kept  from  con- 
tamination by  the  gases  and  other  impurities  always 
present,  especially  when  the  fuel  is  other  than  natural 
gas.  The  pot  furnace  was  the  one  used  by  the  old 
Venetian  glassmakers  in  making  their  beautiful  and 
fragile  glass.  Pot  furnaces  of  an  improved  type  are 
largely  used  today  in  making  cut  or  pressed  glass,  and 
especially  in  making  optical  and  colored  glass  where 
quality  is  of  the  first  importance. 

Fire  Clay 

The  pots  must  be  made  of  a  special  grade  of  fire 
clay.  An  extraordinary  amount  of  care  is  required  in 
the  manufacture. 

Fire  clays  are  clays  which  contain  a  large  amount 


28 


GLASSWARE  DEPARTMENT 


of  silica  and  a  small  percentage  of  fluxes  or  binding 
materials,  so  that  they  can  withstand  a  high  tempera- 
ture. Fire  clay  is  found  in  nearly  every  part  of  the 
United  States,  especially  in  New  Jersey,  Pennsylvania, 
Ohio,  and  Missouri.  The  pot  clay  found  near  St. 
Louis  is  said  to  be  unsurpassed  even  by  the  most  cele- 
brated clays  of  Europe. 

Manufacture  of  Pots 

When  the  clay  has  been  finely  sifted  it  Is  well  mixed 
with  burnt  clay  or  unglazed  fragments  of  broken  pots, 
which  tend  to  bind  it  together.  Skill  is  required  in 
mixing  and  working  the  ingredients  in  order  to  drive 
out  every  particle  of  air  which,  by  expansion  in  the 
furnace,  would  break  the  pots. 

After  the  mixed  material  has  been  made  into  the 
creamy  substance  known  as  "  slip,"  as  if  for  pottery, 
it  is  given  a  definite  shape  by  casting,  molding,  or 
building.  The  practice  is  to  make  several  pots  at  a 
time  so  that  one  may  partially  set  while  another  is 
being  built.  The  pots  are  allowed  to  stand  for  from 
8  to  12  months  in  a  temperature  of  from  90°  to  100° 
F.  They  are  then  placed  on  fire  clay  blocks  in  a  bak- 
ing furnace  and  subjected  to  a  red  heat  (1,800°  to 
2,700*^  F.)  for  several  weeks.  If  they  do  not  crack  or 
melt  at  this  temperature,  they  are  fit  for  use. 


MANUFACTURE  OF  GLASS 


29 


In  addition  to  the  prolonged  heat  of  the  glass  fur- 
nace, the  pots  must  be  able  to  withstand  the  corroding 
effects  of  some  of  the  raw  materials  in  the  batch,  such 
as  red  lead,  potash,  soda,  and  borax.  This  corroding 
may  even  go  so  far  as  to  make  a  *'  specky  '*  glass, 
which  is  formed  by  a  combination  of  the  aluminum, 
usually  found  in  the  pot  clay,  and  the  alkaline  or  metal- 
lic ingredients  of  the  batch.  To  prevent  this,  the  cru- 
cible is  glazed  on  the  inside. 

Tank  Furnaces 

The  tank  furnace  is  a  square  or  rectangular  oven 
with  doors  at  the  ends.  It  varies  in  depth  from  20  to 
42  inches  according  to  its  purpose. 

One  end  is  called  the  "  filling  hole  *'  and  into  this 
the  batch  is  shoveled.  The  other  end  is  called  the 
*'  working  hole  "  and  from  it  the  molten  glass  is  taken 
to  be  molded.  This  arrangement  permits  continuous 
working.  The  portions  of  the  tank  which  come  in 
contact  with  the  molten  material  must  be  made  of  the 
special  grade  of  fire  clay  which  is  used  for  the  pots 
in  the  pot  furnaces.  The  tank  furnace  is  in  reality 
a  single  open  crucible.  In  practice  it  is  often  of  large 
dimensions  and  is  never  closed  nor  covered. 

A  horseshoe  flame  (shown  in  Figure  3)  is  used  in  a 
tank  furnace  and  is  so  regulated  that  each  part  of  the 
furnace  remains  at  the  same  temperature  during  the 


1; 


30 


GLASSWARE  DEPARTMENT 


whole  time  that  the  furnace  is  working.  The  flames 
of  the  fuel  play  over  the  melting  batch  so  that  the 
fusing  is  much  more  rapid  and  efficient,  with  a  result- 
ing economy  of  fuel.  Unfortunately,  exposure  to  the 
atmosphere  and  the  direct  contact  of  the  glass  with 


tflLET  ■^=^ 


exiT 


Figure  3.    Diagram  of  a  Furnace  with  a  Horseshoe  Flame 

hot  gases  in  various  stages  of  combustion,  make  the 
regulation  a  much  more  difficult  and  uncertain  matter 
than  in  the  closed  pots. 

For  making  glass  of  the  finest  quality,  such  as  that 
for  cutting  and  the  best  grades  of  pressed  or  blown 
wares  the  pot  furnace  is  best  suited. 

The  tank  furnace,  on  the  other  hand,  has  the  ad- 
vantage of  producing  glass  of  greater  uniformity,  free 
from  cords  and  streaks,  and  is  therefore  well  adapted 
for  making  blown  ware  such  as  bottles  of  all  sorts, 
lamp  chimneys,  glass  lamps,  thin  blown  tumblers,  etc. 
—  in  fact  any  or  all  articles  in  which  clearness  is  of 
more  value  than  the  color  tint.     Progress  is  being 


MANUFACTURE  OF  GLASS 


31 


made  in  the  building  and  manipulating  of  tanks,  and 
it  is  not  unlikely  that  in  the  near  future  this  type  of 
furnace  will  produce  glass  which  will  in  all  respects 
equal  that  made  in  pots.  Glass  which  is  in  no  respect 
inferior  to  pot  glass  is  even  now  being  made  in  tank 
furnaces.  This,  however,  is  not  through  any  change 
in  furnace  construction,  but  through  increased  knowl- 
edge as  to  the  use  of  decolorizing  materials  which, 
when  added  to  the  glass  batch,  neutralize  objectionable 

tints. 

The  C  tank  is  a  modem  type  of  furnace  invented  in 
1 86 1  and  used  largely  throughout  Europe  and  America. 
It  is  made  from  pot  clay  and  divided  into  "  floating 
compartments,"  each  at  a  lower  level  than  the  one 
immediately  before.  The  raw  material  is  put  in  at  the 
door,  and  as  it  melts,  flows  from  the  first  compartment 
into  the  second,  which  is  the  refining  compartment. 
Here  the  temperature  is  higher  and  the  refining  takes 
place.  From  this  compartment  the  refined  liquid 
passes  into  the  gathering  compartment,  where  at  a 
lower  temperature  it  cools  and  thickens  for  the  form- 
ing. These  furnaces  may  be  worked  continuously  and 
are  in  many  ways  better  than  the  old  style  of  tank 
furnace. 

Calcar  Furnace 

The  calcar  furnace  is  in  the  form  of  an  oven  about 


32 


GLASSWARE  DEPARTMENT 


10  feet  long,  7  feet  wide,  and  2  feet  high,  in  which 
some  of  the  batch  materials  are  partially  melted,  form- 
ing a  pasty  mass  out  of  which  the  moisture  and  gases 
have  been  driven.  This  mass  is  allowed  to  solidify, 
and  while  yet  soft  is  cut  into  squares,  which  are  stored 
for  use  as  frit  or  cullet.  (See  page  22,)  When  these 
frits  are  mixed  with  the  batch  they  hasten  the  process 
of  fusion. 

Fusing  Process 

In  the  case  of  a  tank  furnace  the  batch  is  put  in 
through  openings  in  the  melting  end  by  means  of  long- 
handled  shovels  or  some  mechanical  device,  and  new 
material  is  added  every  half-hour  for  four  or  more 
hours. 

When  pot  furnaces  are  to  be  filled,  the  pots  must 
first  be  entirely  emptied  and  the  temperature  of  the 
furnace  brought  up  to  2,500°  F.  before  the  new  ma- 
terial is  put  in,  since  a  low  or  an  unequal  temperature 
has  a  disastrous  effect  on  the  batch. 

As  in  the  case  of  any  boiling  liquid,  allowance  must 
be  made  in  each  pot  for  the  bubbling  up  of  the  boiling 
mass  so  that  the  pots  may  not  overflow  and  cause  the 
loss  of  valuable  material.  As  they  boil  down,  fresh 
material  is  added;  four  to  eight  fillings  are  custom- 
ary. 


MANUFACTURE  OF  GLASS 


33 


Fining  Process 

The  batch  has  now  become  a  mass  of  foaming,  seeth- 
ing, molten  glass.  Gradually  it  changes  to  a  viscous 
and  entirely  transparent  substance  full  of  gas  bubbles. 
As  any  bubbles  in  the  finished  glass  are  an  obvious 
defect,  however,  their  removal  has  been  provided  for 
by  putting  into  the  batch  some  materials  containing 
oxygen.  The  heat  of  the  furnace  is  increased  until 
this  oxygen  is  freed  and  forms  large  bubbles,  which 
rise  to  the  surface  and  carry  the  smaller  ones  with 
them.  This  is  called  the  fining  process.  The  more 
liquid  the  mass  is,  the  more  readily  will  the  gas  bubbles 
disengage  themselves.  For  this  purpose  "  fluxes  "— 
substances  which  promote  the  chemical  action  just  de- 
scribed —  are  added.  The  glassmaker  sometimes  uses 
arsenic  or  a  substance  containing  moisture,  such  as 
a  potato  attached  to  a  rod. 

When  the  fining  process  is  completed,  the  melter 
takes  out  samples  or  proofs  of  the  liquid  on  a  rod  or  a 
long  spoon  and  examines  them  for  bubbles.  If  im- 
purities have  gathered  the  surface  is  also  skimmed. 

The  melting  and  fining  process  takes  about  24  hours. 
Then  the  temperature  of  the  furnace  is  lowered  to 
working  heat  and  the  shaping  and  working  of  the 
glass  is  begun. 


V 


'ti 


:.         -  ., 


l:1 


ll' 


1  < 


Chapter  IV 

FINISHING  PROCESSES 

Removing  Molten  Glass  from  the  Furnace 

Molten  glass,  as  has  been  said  before,  is  not  liquid 
but  viscous;  as  it  cools  it  passes  to  the  solid  form 
without  crystallization  and  while  cooling  can  be  shaped 
according  to  the  glassmaker's  will.  While  in  this 
semiliquid  condition  glass  has  the  malleability  and  duc- 
tility which  metal  has,  that  is,  it  may  be  hammered  or 
rolled  without  cracking,  and  it  may  be  drawn  out  into 
a  wire.     The  glassmaker  speaks  of  the  molten  glass  as 

"  metal.'* 

There  are  three  methods  of  removing  it  from  the  pot 

or  tank: 

Gathering 

Ladling 

Pouring 

Gathering  is  the  process  of  removing  a  part  of  the 
mass  by  twisting  it  around  the  end  of  a  long  tube.  It 
is  the  method  employed  in  making  all  blown  glass  and 
much  of  the  molded  and  pressed  ware.     Gathering  re- 

34 


FINISHING  PROCESSES 


35 


quires  great  skill,  and  makes  an  admirable  display  of 
dexterity.  Like  the  art  of  juggling,  it  can  be  learned 
properly  only  in  early  youth. 

Ladling  is  the  process  of  transferring  the  molten 
glass  to  large  tables  by  means  of  long  ladles. 

Pouring  is  done  by  machinery  which  lifts  and  tips 
the  heavy  pots  so  that  the  glass  flows  out. 

Methods  of  Shaping  Gathered  Glass 

The  glass  obtained  from  the  pot  by  gathering  is 
shaped  or  formed  by : 

Blowing 
Pressing 
Molding 

Glass-Blowing 

Blowing  is  the  most  primitive  and  characteristic  way 
of  forming  glass.  Formerly  all  glass,  even  that  for 
window  panes,  was  shaped  entirely  by  this  process. 
It  is  the  method  still  used  to  form  the  blanks  for  the 
best  cut  glass  and  for  all  pieces  of  delicate  design. 

The  glassblower's  tools  are: 

-^     Blowing  iron  or  blowpipe 
-^  Working  rod 

"  Battledore  " 

Glass  blowpipe 


I 


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36 


GLASSWARE  DEPARTMENT 


Shears 

Pincers 

Tongs  and  similar  pronged  wooden  tools 

Measuring  stick  and  compass 

Spring  balance 

The  most  important  tools  in  the  process  of  blowing 
are  the  blowpipe  and  working  rod. 

The  blowing  iron  or  blowpipe  is  a  long  hollow  iron 
rod  varying  in  length  from  5  to  6  feet  and  in  diameter 
from  %  to  2  inches,  according  to  the  weight  of  glass 
to  be  gathered. 

The  working  rod  is  a  light,  tapering  rod  of  solid  iron 
varying  much  in  both  length  and  strength.  It  is  used 
to  hold  the  vessel  in  the  last  stages  of  manipulation. 

The  "  battledore  "  is  used  to  flatten  the  square  bot- 
toms of  tumblers  or  other  vessels;  the  glass  blowpipe  in 
expanding  the  opened  end  of  bulbs;  the  shears  in  re- 
moving surplus  glass,  or  cutting  the  ends  of  handles 
or  rods;  the  pincers  in  shaping  the  handles  of  jugs  or 
the  decorative  filigree  work  on  vases ;  tongs  and  simi- 
lar pronged  wooden  instruments  in  handling  and  open- 
ing up  certain  pieces ;  the  measuring  stick  and  the  com- 
pass for  marking  with  wax  the  amount  of  surplus  glass 
to  be  removed  with  the  shears ;  the  spring  balance  in 
comparing  the  weight  of  each  vessel  with  that  of  its 
patterns. 


.1 


Courtesy  of  United  States  Glass  Co. 

Figure  4.     Rolling  Glass  on  Marver 


FINISHING  PROCESSES 


37 


A  *'  marver/'  or  table  upon  which  the  glass  may  be 
rolled  about  while  it  is  being  shaped,  completes  the 
equipment. 

How  a  Glassblower  Works 

The  blower  gathers  a  mass  of  the  viscous  glass  from 
the  pot  on  the  end  of  his  iron  blowing  pipe,  adding 


Figure  5.    The  Evolution  of  a  Tumbler 

more  and  more  as  it  cools  until  he  has  the  amount 
necessary  for  the  article  he  wishes  to  make. 

By  rolling  or  marvering  the  ball  over  the  polished 
surface  of  the  table  just  referred  to,  he  makes  it  uni- 
form in  shape  and  free  from  bubbles.  Figure  4  shows 
this  operation. 

He  then  inflates  the  mass  by  blowing  air  into  it 
through  the  tube,  also  exposing  it  from  time  to  time 


1 


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38 


GLASSWARE  DEPARTMENT 


to  the  heat  of  the  furnace,  which  further  expands  the 
air  until  the  article  is  enlarged  as  much  as  he  wishes. 

Figure  5  shows  the  various  stages  in  the  making  of 
a  tumbler.  The  flat  bottom  is  shaped  by  pressing  the 
lower  end  of  the  elongated  bulb  of  glass  on  the  marver. 

The  process  of  glass-blowing  is  fascinating  to  watch. 
The  shapeless  mass  is  twirled,  pulled,  and  thrown 
about  with  perfect  control  and  ease  until  it  assumes  its 
final,  beautiful  shape.  We  are  accustomed  to  think  of 
glass  as  so  fragile  that  it  can  be  handled  only  with 
great  care  and  this  makes  the  glassblower's  work  seem 
almost  magical. 

The  blowing  of  glass  by  the  breath  may  have  been 
originally  suggested  by  the  bubbles  which  appear  in 
the  molten  glass.  It  was  evidently  practiced  in  Egypt, 
for  Egyptian  monuments  as  early  as  2000  B.  c.  show 
glassblowers  working  with  their  pipes. 

The  blowing  was  done  entirely  by  the  breath  until 
1824  when  M.  Robinet  of  the  Baccarat  factory  in- 
vented the  Robinet  pump,  by  the  aid  of  which  large 
cylinders  could  be  made.  This  gave  rise  to  the  com- 
pressed air  and  automatic  blowing  machines  which  do 
much  of  the  work  today. 

Pressing  Glass 

The  metal  for  pressed  glass  is  gathered  on  a  solid 
iron  rod  from  4  to  6  feet  long,  called  a  "  punty."     The 


FINISHING  PROCESSES 


39 


punty  is  thicker  at  one  end  to  allow  a  good  hand-grip, 
and  forged  at  the  other  end  into  the  shape  of  a  knob. 
The  worker  heats  this  knob,  dips  it  into  the  molten 
glass,  and  by  twisting  it  covers  it  with  a  layer  of  glass, 
which  he  manipulates  into  the  shape  of  a  ball,  and  cools 
until  it  is  nearly  solid.  The  ball  of  glass  is  called 
the  "moil,''  and  is  made  larger  or  smaller  according 
to  the  amount  of  glass  to  be  gathered. 

The  gatherer  now  inserts  the  punty  into  the  pot 
mouth,  dips  the  moil  into  the  liquid  glass,  and  begins 
a  rotary  movement,  slowly  at  first,  then  with  greatly 
accelerated  speed  literally  gathering  up  the  glass,  until 
he  has  the  needed  amount  suspended  in  a  droplike 
fashion  beyond  the  end  of  the  punty.  He  then  carries, 
or  rather  juggles,  the  ball  of  liquid  glass  to  the  con- 
veniently placed  press,  and  drops  it  deftly  into  the 
mold.  Another  worker,  the  presser,  severs  the  con- 
necting thread  between  the  body  of  glass  and  the 
punty  with  a  pair  of  scissors. 

Molds  for  pressed  ware  are  usually  made  of  cast 
iron,  and  are  simply  matrices  of  the  size  and  shape  of 
the  article  to  be  made,  marked  with  any  pattern  which 
is  desired  for  the  outside  of  the  article.  A  plunger, 
forced  into  the  mold  by  a  lever  operated  by  hand  or 
machine,  shapes  the  inside  of  the  article.  The  molds 
must  be  constructed  to  admit  of  a  ready  removal  of 
the  pressed  article.     They  are,   therefore,   either  of 


'! 


■  \\ 


" 


40 


GLASSWARE  DEPARTMENT 


one  solid  piece  of  iron,  from  which  the  article  can  be 
dropped  out  by  turning  it  over ;  or  they  are  made  of  a 
number  of  sections  jointed  and  hinged  together.  The 
latter  sort  are  used  for  shaping  the  more  complex 
forms  of  glassware  or  those  ornamented  with  deep  de- 
signs, as,  for  instance,  an  imitation  of  cut  glass. 

The  temperature  of  mold  and  plunger  is  carefully 
regulated  by  streams  of  air  blown  against  them; 
otherwise  the  surface  of  the  glass  might  be  cracked  or 
roughened. 

When  the  glass  has  hardened  the  plunger  is  removed 
and  the  shaped  article  is  taken  from  the  mold.  It 
must  be  smoothed  on  the  inside  to  remove  the  rough- 
ness made  by  the  plunger  and  if  marks  of  the  mold  are 
left,  plain  pieces  are  reheated  in  the  "  glory  hole,"  as 
the  side  openings  into  the  furnace  are  called. 

Pressed  Glass  Used  in  Imitations 

Pressed  glass  is  made  to  imitate  cut  glass  and  the  old 
hand-carved  art  glass  of  Venice  or  Bohemia. 
There  are  three  ways  of  telling  an  imitation : 

1.  The  angles  of  the  design  in  the  imitation  are 

blunt  and  rounded  instead  of  being  clean  cut 
and  sharp. 

2.  The  design  is  very  symmetrical  and  usually  com- 

monplace. 


FINISHING  PROCESSES 


41 


3.  The  glass  lacks  the  brilliancy  given  by  the 
processes  of  hand-cutting  and  hand-polish- 
ing. 

Molding  is  a  combination  of  the  blowing  and  press- 
ing processes. 

Molding 

A  mass  of  molten  glass  is  gathered  from  the  cru- 
cible on  the  end  of  the  blowpipe.  After  being  mar- 
vered  and  slightly  expanded  it  is  thrust  into  the  mold, 
which  shapes  the  outside  while  continued  blowing 
forms  the  inside.  Molded  glass  differs  from  pressed 
glass  in  the  fineness  of  its  finish,  as  it  is  partly  a  hand- 
process. 

Molds  are  of  many  shapes  and  may  be  of  complex 
construction.  They  may  be  of  two,  three,  or  more 
separate  pieces  hinged  together  so  that  the  molded 
article  may  be  easily  removed. 

They  are  made  of  cast  iron  or  other  metals,  plaster 
of  Paris,  clay,  or  wood.  The  metal  molds  are 
strongest,  but  the  metal  is  apt  to  discolor  the  glass. 
This  difficulty  is  met  by  lining  the  molds  with  wood  or 
carbon.  Cork-lined  molds  are  sometimes  used  to  give 
blown  ware  a  uniform  shape  and  size. 

Figure  13  in  Chapter  XVIII  shows  four  old  Roman 
molded  glass  pieces. 


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42 


GLASSWARE  DEPARTMENT 


Annealing 

After  the  glass  articles  have  been  formed  and  cooled, 
it  is  necessary  to  subject  them  to  a  process  known  as 
annealing. 

Annealing  is  the  reheating  and  cooling  of  the  formed 
glass,  and  is  one  of  the  most  important  operations  in 
glass-making,  since  it  is  this  process  which  makes  it 
resistent  to  blows  and  changes  of  temperature.  Glass- 
ware which  is  not  properly  annealed  is  very  fragile 
and  easily  broken.  Annealing  also  addc  to  the  bril- 
liancy of  the  glass. 

Process  of  Annealing 

The  glass  articles  are  placed  in  annealing  kilns  or 
ovens  (often  known  as  "lehrs"),  and  heated  to  a 
temperature  of  800°  F.  The  heat  is  gradually  raised 
to  1,200°  F.  and  then  gradually  lowered,  so  that  the 
articles  cool  slowly.  It  is  this  gradual  cooling  which 
makes  the  glass  strong,  durable,  and  of  uniform  and 
consistent  texture,  since  the  pores,  expanded  by  the 
heat,  are  allowed  to  contract  evenly  throughout  the 
entire  substance.  When  cooled  quickly  the  surface 
shrinks  more  rapidly  than  the  inside  and  therefore  is 
under  a  greater  strain. 

Large  heavy  pieces  require  a  longer  time  and  greater 
heat  than  small  thin  pieces.  The  time  may  vary  from 
a  few  hours  to  a  week. 


FINISHING  PROCESSES 


43 


Varieties  of  Kilns 

Ordinary  kilns  or  ovens  are  used  for  heavier  articles, 
such  as  blanks  for  cutting  and  plate  glass,  which  must 
remain  in  the  kiln  for  a  considerable  length  of  time. 

The  continuous  lehr  or  kiln  is  used  for  lighter  arti- 
cles. This  style  of  annealing  oven  has  a  long  rectan- 
gular chamber  or  tunnel  of  brick  heated  at  one  end  and 
provided  with  numerous  small  iron  trays  or  trucks, 
which  are  moved  by  an  endless  chain.  The  pieces  of 
glass  are  placed  on  the  trays  at  the  hot  end  and  grad- 
ually moved  towards  the  cooler  part  of  the  oven,  mak- 
ing, room  for  fresh  pieces. 

The  labor  required  for  piling  up  and  taking  down 
the  glass  in  a  kiln  is  saved  by  using  this  continuous 
oven. 

The  famous  Murano  glass  works  (see  Chapter 
XVIII)  had  a  simple  arrangement  for  annealing,  con- 
sisting of  a  tunnel  about  thirty  feet  long,  which  was 
heated  by  the  waste  heat  from  the  melting  furnace. 
It  had  a  tramway  running  down  the  center  with  mov- 
able trucks,  on  which  the  glass  was  drawn  from  one  end 
to  the  other. 

The  intermittent  kiln  or  oven  is  heated  by  gas  and 
fitted  with  a  shelf  on  which  the  glass  is  set.  When 
filled  with  ware  it  is  closed,  heated,  and  allowed  to 
cool;  the  process  is  controlled  by  carefully  regulated 
drafts. 


ii 


I  1 


■  s 


44  GLASSWARE  DEPARTMENT 

A  novel  method  of  annealing  was  invented  by  a 
Frenchman  named  De  la  Bastie.  The  pieces  were 
put  in  a  wire  frame  while  yet  soft  and  immersed  in  a 
hot  liquid,  preferably  mutton  fat.  For  various  reasons 
the  process  was  not  very  successful  and  did  not  dis- 
place the  annealing  oven. 

Polishing 

Much  of  the  beauty  of  glass  is  due  to  its  brilliancy 
and  the  reflection  of  light  from  its  polished  surface.  A 
natural  polish  is  produced  by  the  processes  of  fusing 
and  annealing,  but  in  cut  glass  this  is  destroyed  by  the 
action  of  the  water  and  sand  on  the  cutting  wheels. 
Polishing  is  an  important  feature  of  the  glass-cutting 

process. 

Pressed  glass  is  dulled  by  coming  in  contact  with 
the  sides  of  the  metal  molds,  which  chill  the  surface  too 
quickly.  This  luster  may  be  restored  by  placing  the 
piece  in  the  "  glory  hole,"  where  it  is  held  in  an  intense 
flame,  which  gives  it  what  is  known  as  fire  polish. 

Old  glassmakers  reheated  their  glass  many  times, 
since  each  period  of  heating  and  cooling  added  to  its 

brilliancy.  . 

Today  the  acid  polish,  described  in  Chapter  VI,  is 
given  to  the  better  grades  of  pressed  glass  and  to  all 
but  the  finest  cut  glass. 


FINISHING  PROCESSES 


45 


^ 


Defects  in  Glass 

If  the  materials  of  which  glass  is  made  are  impure 
or  improperly  combined,  the  color  will  be  poor;  for 
instance,  an  excess  of  iron  will  give  a  greenish  or  a 
brown  tinge.  Too  much  manganese  gives  a  pink 
tinge. 

"  Bottle  glass,"  which  is  used  for  the  cheaper  grades 
of  bottles,  is  colored  by  the  iron  and  other  impurities 
which  it  contains. 

Glassmakers  have  trade  terms  for  defective  glass, 
such  as: 

"  Seedy  "  glass,  which  contains  small  air  bubbles 
caused  by  too  rapid  melting  or  too  low  tem- 
perature in  the  furnace. 

"  Stony  "  glass,  which  contains  tiny  lumps  of  un- 
dissolved material  or  clay  from  the  sides  of  pots 
or  tanks. 

"  Cordy  "  or  wavy  glass,  with  waves  or  streaks  of 
crystallized  glass  instead  of  a  clear,  even  tex- 
ture. 

"  High  color  **  is  the  pink  tinge  from  manganese. 

"  Low  color  "  is  the  green  tinge  from  iron. 

Glass  may  be  imperfectly  formed  or  it  may  be  poorly 
finished. 

Cut  glass  should  not  be  cut  too  deeply  and  the  edges, 


v\\ 


■   ( 

1 


46 


GLASSWARE  DEPARTMENT 


i] 


while  clear  and  sharp  to  the  eye,  should  not  be  knife- 
edged  or  rough  to  handle. 

Differences  in  Glass 

Lead  glass  is  heavier  and  more  brilliant  than  lime 
glass,  but  the  difference  is  not  always  apparent  to  the 
untrained  buyer  or  salesperson. 

Pressed  glass  has  a  dull  finish  as  the  result  of  the 
chilling  given  the  hot  molten  glass,  or  "  metal,"  as  it 
is  called,  by  the  mold.  This  may  be  removed  by  re- 
heating, and  the  "  fire  polish  "  is  restored  to  all  good 
pressed  glass. 

Colored  or  decorated  glass  is  subject  to  many  acci- 
dents in  fusing  or  firing  the  color. 

Defective  articles  are  usually  discarded  by  the  manu- 
facturer to  be  sold  as  seconds,  or,  if  too  imperfect,  to  be 
remelted  and  formed  again. 


> 


Chapter  V 

BOTTLES  AND  OTHER  SPECIAL  FORMS 

OF  GLASS 

Bottle-Making 

Bottles  were  among  the  earliest  forms  of  glass  ves- 
sels, and  bottle-making  is  still  a  special  division  of  the 
industry. 

They  are: 

1.  Blown  and  shaped,  by  hand. 

2.  Molded. 

3.  Blown  and  pressed  by  automatic  machines. 

Bottles  made  entirely  by  hand  are  now  found  only  in 
art  glass  or  among  articles  of  luxury.  Even  finely  cut 
bottles  are  usually  molded. 

Blown  Bottles 

For  blown  bottles  the  process  is  as  described  in 
Chapter  IV.  The  molten  glass  is  gathered  on  the  blow 
pipe,  rolled  or  marvered  on  the  flat  metal  plate,  and 
blown  with  the  breath  until  it  is  nearly  the  required 
size.     During  the  process  the  pipe  is  swung  gently  to 

47 


1 


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48 


GLASSWARE  DEPARTMENT 


SPECIAL  FORMS  OF  GLASS 


and  fro,  so  that  the  glass  settles  downward,  leaving  a 
thinner  part  next  the  pipe  to  form  the  neck.  It  is  then 
reheated  and  is  either  blown  into  a  mold  of  fire  clay  or 
metal,  or  shaped  by  hand  tools.  If  there  is  to  be  a  con- 
cave bottom,  as  in  wine  bottles,  this  is  made  by  pushing 
up  the  hot  glass  by  means  of  an  iron  rod  called  a  pontil, 
upon  which  a  small  mass  of  glass  has  been  gathered. 

The  bottle  is  now  attached  to  both  the  pontil  and  the 
pipe,  but  by  chilling  the  glass  the  pipe  is  broken  off  at 
the  point  where  the  neck  is  to  end.  The  lieck  is  heated 
to  make  it  smooth,  and  a  thread  of  glass  is  wound 
round  it  to  give  the  proper  stiffness  and  finish. 

By  various  inventions  machinery  has  been  substi- 
tuted for  each  of  these  processes  in  bottle-making. 

Molded  Bottles 

The  first  change  consisted  in  operating  the  mold  by 
a  lever,  one-half  of  the  mold  being  attached  to  the 
floor  and  the  other  raised  by  the  workman  by  means 
of  a  rod.     This  mold  gave  the  bottle  its  final  shape. 

By  another  machine  the  glass  is  gathered  on  an  iron 
rod  and  dropped  into  a  measuring  mold,  which  assures 
the  right  quantity.  This  material  is  then  forced  into 
a  neck  mold,  which  gives  the  shape  of  the  neck  of  a 
bottle.  While  the  neck  mold  is  still  firmly  attached  a 
plunger  is  forced  down  through  the  material  and  then 
by  means  of  compressed  air  the  lower  part  of  the 


49 


bottle  is  blown  out  to  the  proper  length  and  fitted  into 
a  third  mold,  called  the  finishing  mold.  Levers  open 
the  finishing  and  neck  molds  at  the  same  time  and  re- 
lease the  perfect  bottle.  This  machine  is  capable  of 
producing  120  bottles  per  hour. 

The  Owens  Automatic  Bottle  Machine 

The  automatic  machine  takes  the  place  of  human 
hands  and  requires  no  skilled  workmen  at  all.  A  fur- 
nace is  built  with  revolving  pots,  in  front  of  which 
the  machine  is  placed.  As  the  pots  revolve,  the 
machine,  driven  by  an  electric  motor,  moves  with  them. 
It  has  either  six  or  ten  arms  carrying  **  blanks  "  and 
finishing  molds.  As  each  blank  mold  passes  over  the 
pot  the  molten  glass  is  sucked  up  into  it  by  a  vacuum 
process,  which  is  regulated  to  supply  just  the  right 
quantity  for  the  bottle  required.  The  neck  is  formed 
while  the  glass  is  in  this  first  mold. 

Then  the  blank  mold  opens  and  the  glass  is  shown 
as  a  white-hot  cylinder  supported  by  the  neck;  the 
finishing  mold  rises  and  closes  over  it  and  the  shape  is 
finished  by  the  application  of  compressed  air.  After 
making  a  complete  turn  the  machine  drops  out  the  fin- 
ished bottle,  which  is  put  into  the  tempering  ovens  and 
travels  slowly  towards  the  cool  end,  where  it  is  ready 
to  be  packed  and  shipped. 

The  regularity  of  the  mechanical  process  and  the 


!:;; 


!:i 


Ml 


50 


GLASSWARE  DEPARTMENT 


even  pressure  of  the  air  produce  bottles  of  a  uniform 
strength  and  quality. 

Glass  for  Insulation 

As  glass  is  a  non-conductor  of  electricity  and  a  very 
poor  conductor  of  heat  it  is  the  best  material  for  insula- 
tion. Telephone  and  telegraph  wires  are  wound  on 
glass  caps  to  prevent  the  loss  or  transference  of  the 
electricity.  The  recent  shortage  of  timber  in  Europe 
has  occasioned  the  use  of  telegraph  pole*;  which  have 
a  frame  work  of  woven  wire  in  the  center  but  are 
otherwise  made  entirely  of  glass.  These  poles  will 
neither  rot,  rust,  nor  be  destroyed  by  insects  and  are 
therefore  worth  a  greater  original  cost. 

Spun  glass  is  used  as  insulating  material  in  electrical 
ovens,  which  will  retain  their  heat  for  a  long  time 
after  the  current  has  been  cut  off. 

Bullet-Proof  and  Safety  Glass 

One  of  the  greatest  objections  to  the  commercial 
use  of  glass  is  its  brittleness,  which  not  only  causes  it 
to  break  easily  but  to  splinter  and  fly  under  mechanical 
shock  and  cause  very  serious  accidents. 

Bullet-proof  glass  was  invented  for  war  use  and 
various  forms  of  safety  glass  are  made  in  a  way  that 
prevents  this  splintering.  The  glass  is  made  in  two  thin 
sheets   with   a   layer    of   transparent,    shock-resisting 


SPECIAL  FORMS  OF  GLASS 


51 


material  between,  and  the  three  layers  are  fused  into 
a  solid  sheet.  The  adhesion  is  so  perfect  that  it  looks 
like  ordinary  glass  but  when  struck  with  great  force 
it  will  only  crack.  The  splinters  are  held  by  the  bind- 
ing material  and  cannot  fly  off.  Safety  glass  is  chiefly 
used  for  wind-shields,  headlights,  and  lenses  for  auto- 
mobiles and  for  goggles.  During  the  war  gas-mask 
lenses,  aviators'  goggles,  and  aeroplane  wind-shields 
were  made  of  it. 

Wire  glass  is  an  older  material  made  on  the  same 
principle.  A  wire  mesh  is  inserted  between  two  layers 
of  rolled  plate  for  use  in  the  windows  of  factories, 
gymnasiums,  etc.,  where  it  is  subject  to  jarring  or 
striking,  and  also  as  a  protection  against  fire.  The 
metal,  however,  affects  the  transparency  of  the  glass 
as  well  as  being  itself  quite  visible,  while  the  binding 
material  in  safety  glass  is  not. 

Colored  Glass 

Mosaics  are  composed  of  glass  with  the  addition 
of  various  mineral  compounds.  The  glass  is  melted 
and  mixed  with  colored  powders  until  it  becomes  a 
thick  mass.  Then  the  mass  is  slowly  baked  until  it 
has  reached  the  required  degree  of  hardness,  when  it 
is  taken  out  and  molded  into  small  cubes,  or  "palettes." 

In  making  a  mosaic  picture  the  artist  sketches  the 
design  with  charcoal  on  a  slab  of  plaster.    Small  holes 


!  11 

4 


52 


GLASSWARE  DEPARTMENT 


are  hollowed  out  with  a  piercer  and  the  mosaic  cubes 
are  chipped  to  fit  in  the  holes  where  they  are  held  by 
means  of  a  glue  or  cement. 

In  the  city  of  Lyons  glass  pavements  have  been 
recently  laid.  They  are  composed  of  **ceramo  crystal," 
a  devitrified  glass  in  blocks  8  inches  square.  This  is  a 
return  to  the  mosaic  glass  pavements  used  by  the 

Romans. 

Colored  glass  is  used  for  many  other  purposes,  useful 
and  decorative.  Among  the  former  is  the  use  of  ruby, 
green,  and  purple  glass  for  signaling  purposes  in  rail- 
ways, motor  cars,  and  lighthouses.  Photography  also 
makes  extensive  use  of  colored  light  for  various  pur- 
poses, and  medical  science  and  beauty  doctors  require 
colored  light. 


Part  II— Cut  Glass  and  Tableware 


Chapter  VI 

CUT  GLASS 

Characteristics 

There  are  three  grades  of  glass  which  are  known 
as  cut  glass.  The  best  grade  is  cut  entirely  by  hand ; 
the  second  grade  is  first  pressed  and  then  finished  by 
hand;  the  third  is  merely  pressed  in  patterns  which 
imitate  cut  glass. 

Genuine  cut  glass  has  four  characteristics  known  to 
the  expert.     These  are : 

1.  Its  color  —  a  clear,  brilliant  white  tinged  with 

steely  blue 

2.  Its  bell-like  resonance  when  struck 

3.  Its  weight 

4.  Its  fine  finish 

These  characteristics  depend  upon  the  materials  of 
which  it  is  made  and  also  upon  the  process  of  manu- 
facture. A  well-known  manufacturer  recently  gave 
the  following  definition :     "  Cut  glass  is  and  always 

53 


A-- 


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GLASSWARE  DEPARTMENT 


has  been  a  piece  of  crystal  cut  on  wheels.  The  design 
is  cut  in,  not  pressed  in,  nor  blown  in ;  and  it  is  polished 
by  hand.  Genuine  cut  glass  is  not  then  partly  re- 
touched, pressed  lime  glass." 

An  authority  on  testing  cut  glass  says :  "  First  note 
that  the  article  is  really  cut.  This  can  be  detected  by 
the  sharp  edges  of  the  design  as  well  as  by  the  delicacy 
and  intricacy  of  the  design  itself.  Second,  tap  with  a 
pencil.  If  the  glass  contains  lead,  a  necessary  ingre- 
dient of  all  good  cut  glass,  it  will  resound  like  the  ring 
of  a  deep-toned,  silvery  bell." 

Materials 

The  materials  from  which  genuine  cut  glass  or  cut 
crystal  is  made  are : 

Silica  or  pure  sand 
Oxide  of  lead 
Potash 

About  60  pounds  of  lead  are  used  for  each  100 
pounds  of  silica;  the  lead  gives  weight,  resonance,  and 
brilliancy  and  also  keeps  the  glass  soft  for  cutting. 
The  potash  is  used  to  clarify  the  glass  and  to  add  to  the 
scintillating  effect.     All  the  materials  must  be  pure. 

Process 
The  earlier  stages  of  the  process  are  the  same  as  for 


CUT  GLASS 


55 


blown  glass,  that  is,  making  the  blank,  the  rough  shape 
resembling  the  general  outlines  of  the  piece  to  be 
copied,  includes  : 

Gathering  the  material 
Blowing  into  shape 
Annealing 

There  are  certain  differences.  The  roughly  shaped 
"  blank  "  is  heated  three  times  and  worked  over  by 
three  different  workmen.  In  the  annealing  oven  the 
glass  is  brought  to  a  particularly  high  temperature  and 
is  cooled  very  gradually. 

The  blanks  for  cut  glass  are  blown  much  thicker 
than  for  articles  which  are  not  to  be  cut,  particularly 
if  the  piece  is  large  and  the  incision  must  be  deep. 
Some  pieces  lose  over  one-third  of  their  original 
weight  during  the  cutting  process. 

Designing  and  Cutting 

The  second  part  of  the  process  is  quite  different.  It 
includes : 

Tracing  the  outline  of  the  design 
Roughing 
Smoothing 
Cutting  fine  lines 
Polishing 
The  shaped  blanks  are  stored  on  the  shelves  of  the 


in 


56 


GLASSWARE  DEPARTMENT 


factory  in  which  the  cutting  is  to  be  done.     Each  large 
glass-cutting  establishment  employs  its  own  artists 
who  design  both  the  shapes  and  the  decorations  of  is 
pieces     The  designs  must  be  mathematically  accurate 
and  suited  to  the  spaces  they  are  to  occupy. 

Tracing  the  Design 

First  the  design  is  outlined  with  a  brush  in  red  lead 
and  turpentine,  or  transferred  from  a  stencil  or  a  cop- 
perplate  pattern. 

Cutting  Wheels 

Glass  is  cut  on  wheels  made  both  of  steel  and  of 
stone.     These  wheels  may  vary  in  diameter  from  i /a 
inches  to  3  feet,  and  in  thickness  from  %  of  an  inch  to 
I  inch     They  are  driven  by  steam,  gas,  or  electrical 
power.     The    larger    wheels    are    used    for    cuttmg 
straight  lines  and  the  smaller  ones  for  curved  lines. 
The  sharper  the  curve,  the  smaller  must  be  the  wheel. 
The   face  of   the   wheel  may  be  round,   square,  or 
pointed.     As  many  as  fifteen  or  twenty  different J.mds 
of  wheels  of  different  degrees  of  hardness  are  used  m 
the  cutting  process.     Figure  6  shows  the  cuttmg  room 

'" M  einste'and  novel  form  of  cut  glass  is  made 
by  stone  engraving,  a  form  of  cutting  done  entirely 
by  hand  with  stone  wheels  and  copper  tools.    The  de 


INTENTIONAL     SECOND  EXPOSURE 


56 


GLASSWARE  DEPARTMENT 


factory  in  which  the  cutting  is  to  be  done.  Each  large 
glass-cutting  establishment  employs  its  own  artists, 
who  design  both  the  shapes  and  the  decorations  of  its 
pieces.  The  designs  must  be  mathematically  accurate 
and  suited  to  the  spaces  they  are  to  occupy. 

Tracing  the  Design 

First  the  design  is  outlined  with  a  brush  in  red  lead 
and  turpentine,  or  transferred  from  a  stencil  or  a  cop- 
perplate pattern. 

Cutting  Wheels 

Glass  is  cut  on  wheels  made  both  of  steel  and  of 
stone.  These  wheels  may  vary  in  diameter  from  i/4 
inches  to  3  feet,  and  in  thickness  from  %  of  an  inch  to 
I  inch.  They  are  driven  by  steam,  gas,  or  electrical 
power.  The  larger  wheels  are  used  for  cutting 
straight  lines  and  the  smaller  ones  for  curved  lines. 
The  sharper  the  curve,  the  smaller  must  be  the  wheel. 
The  face  of  the  wheel  may  be  round,  square,  or 
pointed.  As  many  as  fifteen  or  twenty  different  kinds 
of  wheels  of  different  degrees  of  hardness  are  used  in 
the  cutting  process.  Figure  6  shows  the  cutting  room 
in  a  glass  factory. 

An  expensive  and  novel  form  of  cut  glass  is  made 
by  stone  engraving,  a  form  of  cutting  done  entirely 
by  hand  with  stone  wheels  and  copper  tools.     The  de- 


CUT  GLASS 


57 


signs  are  chiefly  vines  and  flowers  and  are  not  cut  deep. 
This  is  sometimes  mistaken  for  pressed  glass. 

Expert  Knowledge  Required 

Glass  cutters  must  be  expert  workmen,  as  their 
material  is  heavy  and  yet  easily  broken  and  mistakes 
can  seldom  be  corrected.  The  operator  holds  the  blank 
against  the  wheel  with  just  the  right  amount  of  pres- 
sure for  the  speed  of  the  wheel ;  the  vibration  of  the 
glass  will  cause  it  to  crack,  unless  skilfully  handled. 
The  operator  judges  the  proper  pressure  by  feeling  as 
much  as  by  sight. 

Elaborate  pieces  require  several  weeks  for  cutting 
and  polishing  and  the  labor  cost  is  very  heavy. 

Roughing 

The  "  roughers  '*  are  workmen  who  make  a  rough 
outline  of  the  design,  following  the  larger  lines  and 
cutting  the  deep  incisions.  This  is  done  on  steel  wheels 
about  2%  feet  in  diameter.  A  steel  wheel  is  also  used 
to  make  the  bottom  of  the  piece  level.  In  some  cases  a 
wheel  of  carboniferous  sandstone  is  used  instead  of 
steel. 

As  the  wheel  cuts  into  the  glass,  a  stream  of  water 
and  sand  made  from  garnet  and  hornblende  trickles 
over  it  from  a  can  suspended  above.  This  stream  of 
water  and  sand  assists  the  cutting  and  makes  it  almost 


58 


GLASSWARE  DEPARTMENT 


CUT  GLASS 


59 


noiseless.     When  the  process  is  finished,  the  glass  has 
a  frosted  or  milky  appearance. 

Smoothing 

When  the  deep  lines  have  been  cut,  the  design  is  re- 
fined and  smoothed  upon  a  wheel  of  black  cragleith 
stone  without  the  use  of  sand  or  emery.  Cragleith  is 
a  famous  stone  from  Edinburgh  which  contains  no 
sand.  The  stone  wheel,  which  resembles  the  steel  one 
in  size  and  shape,  smooths  the  deep  incisions  and  gives 
the  glass  a  gray,  satiny  finish  which  enables  it  to  take 
a  high  polish. 

Another  stone  which  is  used  in  the  process  is  called 
alundum,  an  artificial  composition  of  a  special  kind  of 
clay  called  bauxite.  The  clay  has  been  subjected  to 
an  electrical  current,  reduced  to  crystals,  crushed  to 
powder,  and  then  mixed  with  sand,  salt,  and  sawdust, 
and  burned  in  a  kiln. 

The  piece  now  goes  back  to  the  stencil  operators, 
usually  girls,  who  put  in  the  design  for  the  finer  cut- 
ting—  the  stars,  checkerwork,  light  criss-cross  lines, 
etc.  This  cutting  is  done  on  a  stone  wheel  and  re- 
quires great  skill  and  accuracy. 

Polishing 

After  the  complete  design  has  been  cut,  the  piece  is 
taken  to  the  polisher,  who  manipulates  a  wooden  wheel 


charged  with  emery  or  rouge,  a  polishing  material. 
This  process  removes  all  roughness  and  polishes  both 
the  cut  and  the  uncut  surface.  Sometimes  a  hard  fiber 
brush  is  used  or  a  cork  wheel  and  powdered  pumice- 
stone.  To  give  a  high  gloss  the  buffmg  wheel  is  used 
— a  sort  of  pad  made  of  pressed  wool.  It  is  covered 
first  with  pumice-stone  and  water  and  then  with  putty 
powder,  both  of  which  give  a  brilliant  polish. 

Figured  Blank  Glass 

The  next  grade  of  "  cut  "  glass  is  far  less  expensive. 

It  is  known  as  the  "  figured  "  blank  glass,  because 
while  it  is  made  of  the  same  materials  as  the  genuine 
crystal,  the  process  is  simpler.  The  molten  glass  is 
blown  into  a  mold,  which  not  only  gives  it  the  desired 
shape  but  leaves  the  design  upon  it. 

The  design  is  then  sharpened  and  finished  upon  a 
wheel  and  the  glass  is  polished  with  acid.  The  best 
lime  blanks  are  treated  in  the  same  way. 

Lime  is  much  cheaper  than  lead.  It  makes  a  harder 
glass  and  one  that  is  lighter  in  weight,  but  without  the 
crystal  white  color,  brilliancy,  or  clear  metallic  ring  of 
the  lead-potash  glass.  The  lime  blanks,  moreover,  are 
usually  only  partly  cut ;  the  heavier  parts  of  the  design 
having  been  pressed  in  and  the  piece  merely  finished  off 
by  hand.  Lime-crystal  blanks,  however,  when  made 
of  fine  materials  and  carefully  finished,  produce  a  glass 


6o 


GLASSWARE  DEPARTMENT 


of  fine  quality  at  about  half  the  cost  of  lead  glass. 
Trade  names,  such  as  ''  semicut,"  or  "  floral-cut,"  are 
given  to  lime  blanks,  which  may  be  partly  cut  or  only 

pressed. 

The  inferior  imitation  is  of  ordinary  bottle  glass 

made  of  inferior  and  impure  materials,  and  merely 
pressed  into  designs  which  resemble  cut  glass.  Both 
kinds  of  imitation  cut  glass  are  polished  with  acid 
rather  than  by  hand. 

Acid  Polishing 

The  glass  is  carefully  washed  in  soap  and  water, 
dried,  and  brushed  on  the  inside  with  melted  paraffin. 
It  is  then  dipped  three  times  into  a  vessel  filled  with 
hydrofluoric  acid,  which  eats  away  the  sharp  edges  and 
gives  it  brilliancy.  After  the  wax  has  been  removed, 
the  piece  is  again  washed  with  a  pure  soap,  wiped  with 
a  linen  towel,  and  wrapped  in  silver  tissue  paper  ready 

for  shipping. 

Genuine  cut  glass  with  careful  handling  retains  both 
its  brilliancy  and  color,  but  glass  made  with  lime  and 
soda  is  not  only  less  brilliant  than  lead-potash  glass 
when  it  is  first  made,  but  if  the  materials  are  impure  it 

darkens  with  age. 

The  acid  polish  is  quick  and  clean,  but  it  produces  a 
wavy  appearance  and  a  peculiar  hard  sheen  instead  of 
the  smooth,  deep  brilliance  produced  by  friction  on 


CUT  GLASS 


6i 


wooden,  felt,  and  cork  wheels.  Glass  finished  by  acid 
polish  is  also  more  quickly  clouded  by  moisture  in  the 
air  and  must  be  cleaned  more  often. 

Glass-Cutting  Machines 

Glass-cutting  machines  have  recently  been  invented 
which  will  make  still  another  distinction,  in  addition  to 
the  hand-cut,  partly  cut,  and  pressed  ware.  These 
machines  have  not  been  used  long  enough,  however,  to 
judge  of  their  effect  on  the  market 

How  to  Judge  Values 

In  judging  of  the  value  of  any  hand-made  product 
as  compared  with  one  made  by  machine,  there  are 
always  two  things  to  be  considered : 

1.  The  real  beauty,  individuality,  finish,  and  du- 

rability of  the  hand-made  article. 

2.  A  "  collector's  value,*'  due  to  the  fact  that  hand- 

made articles  are  more  costly  to  make  and 
therefore  can  be  in  the  possession  of  only  a 
few  fortunate  persons. 

Both  of  these  considerations  are  important  in  the 
case  of  cut  glass.  The  luster,  finish,  and  durability 
of  hand-cut  lead  blanks  are  all  greater  than  in  any  of 
the  imitations.  This  beauty  is  partly  dependent  on  the 
designs,  which  differ  widely  in  their  effectiveness. 


62 


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.  i 


Differences  Between  English  and  American  Glass 

Nearly  all  the  English  patterns  are  what  are  called 
straight  or  miter  cuts,  that  is,  the  lines  are  straight 
rather  than  curved.     They  consist  of ; 

Splits 

Olives 

Prisms 

Hobnail,  or  blunt-cornered  diamonds 

Flutes 

Fringes 

Strawberry  diamonds 

Stars 
Figure  8  in  Chapter  X  shows  several  examples  of 

miter  cuttings.  ,  u        .^ 

The  best  EngHsh  glass  is  called  rock  crystal,  because 

of  its  resemblance  to  the  clear  sparkling  stone  of  that 

name.  , ,  .    ,       .,  ^ 

American  cut  glass  is  considered  by  some  judges  Ae 

best  in  the  world  and  has  been  exported  to  Europe  for 

a  good  many  years;  though  for  a  long  time  merchants 

in  this  country  were  afraid  to  acknowledge  that  ,   was 

of  domestic  manufacture  and  therefore  called  it  im- 

^°Fan  scallops,  rosettes,  curved  and  floral  patterns 
have  been  developed  recently  as  the  result  of  American 
ingenuity. 


Courtesy  of  C.  Dorflinger  &  Sons 

Figure  7.    Cut  Glass  Goblet  in  Poppy  Design 


.  ( 


i^l 


V    I 


INTENTIONAL  SECOND  EXPOSURE 


62 


GLASSWARE  DEPARTMENT 


Differences  Between  English  and  American  Glass 

Nearly  all  the  English  patterns  are  what  are  called 
straight  or  miter  cuts,  that  is,  the  lines  are  straight 
rather  than  curved.     They  consist  of : 

Splits 

Olives 

Prisms 

Hobnail,  or  blunt-cornered  diamonds 

Flutes 

Fringes 

Strawberry  diamonds 

Stars 
Figure  8  in  Chapter  X  shows  several  examples  of 

miter  cuttings. 

The  best  English  glass  is  called  rock  crystal,  because 
of  its  resemblance  to  the  clear  sparkling  stone  of  that 

"" American  cut  glass  is  considered  by  some  judges  the 
best  in  the  world  and  has  been  exported  to  Europe  for 
a  good  many  years;  though  for  a  long  time  merchants 
in  this  country  were  afraid  to  acknowledge  hat ,  was 
of  domestic  manufacture  and  therefore  called  it  im- 

^°?an  scallops,  rosettes,  curved  and  floral  patterns 
have  been  developed  recently  as  the  result  of  Amencan 
ingenuity. 


Courtesy  of  C.  Dorflinger  &  Sons 
Figure  7.     Cut  Glass  Goblet  in   Poppy  Design 


CUT  GLASS  63 

Popular  floral  patterns  are  the: 
Scotch  thistle 
Rambler  rose 
Daisy 
Poppy 
Lily 
Lotus 
Grape 

A  combination  of  miter  and  floral  patterns  is  often 
seen,  in  which  the  sides  of  a  piece  are  miter-cut  and 
the  bottom  decorated  with  a  floral  pattern.  The  miter 
patterns  may  be  pressed  and  the  flowers  cut  with  a 
"  mat "  or  frosted  finish  which  gives  the  piece  individ- 
uality. 

Floral  cutting  is  much  more  delicate  and  graceful 
than  the  stiff  miter  cutting,  though  the  latter  is  very 
effective  in  large,  heavy  pieces.  The  deeper  cuts  are 
brilliant,  but  the  lighter  ones  are  easier  to  keep  clean. 

Figure  7  illustrates  a  beautiful  example  of  floral 
cutting  —  a  goblet  cut  in  poppy  design. 

Cut  Rock  Crystal 

Cut  rock  crystal  is  a  very  beautiful  form  of  cut 
glass  which  has  the  shimmering  luster  and  wavelike 
appearance  of  moving  water  instead  of  the  brilliancy 
of  more  familiar  types.     It  is  an  excellent  copy  of  the 


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GLASSWARE  DEPARTMENT 


CUT  GLASS 


65 


genuine  rock  crystal  which  is  so  rare  that  it  is  seldom 
found  except  in  the  cabinets  of  collectors. 

The  cutting  is  in  fine,  delicate,  floral  patterns  which 
resemble  the  tracing  of  engraving. 

Genuine  Rock  Crystal 

A  brief  description  has  already  been  given  of  rock 
crystal.  It  is  a  colorless,  transparent  form  of  quartz  or 
crystallized  silica.  It  looks  like  a  brilliant  and  beauti- 
ful form  of  glass,  but  differs  from  it  in  being  crystal- 
lized. It  was  first  found  in  Europe  in  the  highest 
peaks  of  the  Alps  Mountains,  and  for  many  centuries 
was  supposed  to  be  ice  frozen  so  hard  that  it  could  not 
be  thawed. 

Works  of  Art  Carved  from  Rock  Crystal 

The  Romans  carved  cups  and  vases  of  rock  crystal, 
some  of  them  of  remarkable  size,  but  it  was  used  more 
generally  in  the  middle  ages.  Altar  crosses  and  other 
church  ornaments  were  made  from  it,  and  it  adorned 
the  palaces  of  kings.  In  1351  the  throne  and  the  foot- 
stool of  a  French  king  were  made  of  the  clear,  spark- 
ling crystal,  and  Catherine  de  Medici  had  a  collection 
of  magnificent  vases  of  the  same  material.  Some  of 
these  treasures  are  set  with  precious  stones  and  in- 
crusted  with  gold  and  silver. 

Rock  crystal  is  very  durable  and  much  less  easily 


scratched  than  glass.  It  has  sometimes  been  sold  as  a 
diamond  when  cut  like  a  gem.  While  it  is  still  used  in 
rings  and  pendants  in  some  countries  of  the  far  east, 
it  is  usually  found  in  larger  pieces  and  ornamented 
with  beautiful  carving.  The  merchants  of  Venice 
probably  introduced  it  to  western  Europe.  It  was 
found  later  in  the  Italian  and  the  French  Alps,  and  also 
in  Hungary,  Iceland,  and  Madagascar.  The  United 
States  is  now  the  principal  source  of  supply. 

Crystal  carving  is  closely  allied  to  the  work  of  the 
goldsmith,  and  has  been  associated  with  the  cutting 
of  cameos  and  semiprecious  stones.  Though  it  often 
appears  in  large  vessels,  most  of  these  pieces  are 
composed  of  several  smaller  fragments  joined  together 
by  gold  or  silver.  Some  magnificent  specimens,  how- 
ever, are  carved  out  of  a  single  piece  with  no  orna- 
ment except  the  exquisite  handiwork. 

There  are  very  fine  collections  of  rock  crystal  in 
Paris,  Dresden,  Vienna,  Berlin,  London,  and  Madrid. 
The  J.  P.  Morgan  collection,  formerly  at  the  Metro- 
politan Museum  in  New  York  City,  and  the  Altman 
collection  have  been  considered  the  finest  in  this 
country. 


n 


i 


Chapter  VII 

ENGRAVED,  ETCHED.  AND  CARVED 

GLASS 

Methods  of  Decoration 

The  surface  of  glass  may  also  be  decorated  by 
means  of  friction  by  cutting  instruments.  These 
forms  of  decoration  are  known  as : 

Engraving 

Etching 

Frosting 

Carving  or  Embossing 

Trailing 

Engraving 

Engraving  is  hand-work ;  the  design  is  either  cut  out 
by  a  copper  disc  operated  by  foot-power  or  machinery 
or  else  by  rapidly  revolving  spindles.  The  glass  is 
held  against  the  disc  or  the  spindle  by  the  operator's 
hands.  Engraving  is  usually  a  line  design,  but  elab- 
orate scenes  can  be  sketched  by  means  of  the  spindles, 
as  in  the  case  of  Bohemian  glass.     The  depth  and 

66 


ENGRAVED,  ETCHED,  CARVED  GLASS    67 

width  of  the  lines  can  be  varied  by  changing  the  disc 
or  the  spindle. 

Etching 

Etching  is  done  by  means  of  hydrofluoric  acid,  the 
only  acid  which  will  attack  glass.  The  piece  of  glass 
to  be  etched  is  covered  with  some  substance  called  the 
"resist,"  on  which  the  acid  has  no  effect.  The  sub- 
stances commonly  used  for  the  purpose  are  beeswax, 
paraffin,  tallow,  resin,  rubber  compounds,  and  metallic 
lead.  Beeswax  is  quite  expensive  but  very  satisfac- 
tory because  it  melts  easily  and  may  be  applied  with 
a  brush,  and  because  it  is  also  easily  removed. 

The  two  processes  employed  are: 

Needle-Etching 
Plate-Etching 

Needle-Etching 

For  needle-  or  machine-etching  small  needles  are  ar- 
ranged in  moving  arms,  which  pierce  through  the  resist 
and  outline  the  pattern  on  the  glass.  The  machines 
are  operated  by  electricity  or  by  compressed  air.  The 
article  is  then  immersed  in  hydrofluoric  acid,  which 
instantly  attacks  the  uncovered  glass.  Needle-etched 
designs  are  always  symmetrical — a  series  of  straight  or 
zigzag  lines,  circles,  curves,  etc. 


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GLASSWARE  DEPARTMENT 


Plate-Etching 

This  method  allows  much  greater  freedom  of  design, 
but  it  also  requires  skilled  labor  and  is  therefore  more 
expensive.  The  design  is  first  cut  in  a  metal  plate  and 
then  a  print  is  taken  from  die  plate  on  tissue  paper. 
From  the  tissue  paper  print  it  is  transferred  to  the 
glass,  which  is  then  coated  with  the  resist  around  all 

of  the  design. 

After  the  acid  has  eaten  out  the  pattern,  the  wax  is 
removed  by  placing  the  article  in  boiling  water  and 
steam.  Ten  distinct  processes  are  required  for  plate- 
etching,  but  beautiful  results  may  be  obtained. 

Sand-Blast  Etching 

In  this  species  of  etching  the  design  is  cut  by  means 
of  streams  of  sand,  which  are  blown  against  the  glass 
by  compressed  air  or  steam.  The  process  was  invented 
in  1876  by  a  Philadelphian.  who  conceived  the  idea 
from  the  dulling  of  lighthouse  glass  by  the  sand  blown 
against  it  in  times  of  storm. 

The  glass  is  prepared  as  for  acid-etching,  the  sur- 
face being  covered  with  a  resist  such  as  rubber,  resin, 
tallow,  or  even  tinfoil  or  paper  out  of  which  the  design 
is  cut  The  stream  of  sand  is  then  applied  and  grad- 
ually cuts  away  the  glass,  leaving  a  dull  or  frosted  sur- 
face. The  effect  is  varied  by  using  wet  instead  of  dry 
sand,  and  by  varying  the  degrees  of  fineness.    The 


ENGRAVED,  ETCHED,  CARVED  GLASS   69 

finer  the  sand  and  the  less  the  pressure  of  the  blast,  the 
more  delicate  the  design.  Sharp  sand  gives  the  best 
result.  Seashore  sand  is  ineffective,  as  its  cutting 
edges  have  been  worn  away  by  the  constant  action  of 
the  water. 

Frosting 

Frosting  is  now  done  either  by  acid  or  the  sand-blast^ 
but  was  originally  produced  by  rolling  the  piece  in 
finely  powdered  glass  while  it  was  still  soft  enough  to 
receive  a  thin  coating  of  the  glistening  particles. 
Frosted  glass  was  first  produced  in  Bohemia,  where  it 
was  designed  to  imitate  the  coating  made  on  glass  by 
frost  in  winter.  The  designs  were  therefore  more  like 
a  delicate  lace-work  than  a  definite  pattern.  The  Ve- 
netians made  frosted  glass  in  beautiful  colors,  but  they 
were  never  so  appropriate  as  the  white  frost-work. 

Carving 

The  design  is  roughly  outlined  on  the  glass  with 
acid  and  then  cut  away  with  small  steel  gravers.  It 
is  very  delicate  work,  requiring  a  rather  soft  glass  and 
most  careful  manipulation  of  the  tools,  which  are  either 
operated  entirely  by  hand  or  struck  lightly  with 
wooden  mallets. 

Embossing 
This  process  is  the  reverse  of  etching  in  that  the 


70  GLASSWARE  DEPARTMENT 

designs  are  raised  on  the  glass.  The  resist  is  made  to 
cover  the  design.  When  the  background,  left  exposed, 
has  been  eaten  away  by  acid,  the  design  is  left  standing 
out  in  relief.  The  designs  are  usually  large,  simple, 
and  conventional. 

Trailing 

Designs  mav  be  applied  to  the  glass  when  it  is  in  the 
viscous  state  by  fusing  fresh  pieces  on  it  instead  of 
cutting  into  the  surface.  This  is  called  trailing,  as 
the  design  is  usually  worked  out  in  trails  of  vines  or 
similar  figures.  It  is  one  of  the  ways  of  applymg  color 
and  is  much  used  in  Venetian  glass. 


Chapter  VIII 

TABLEWARE 

The  largest  division  of  table  glass  is  stemware 
which  includes  sherbet  and  grapefruit  glasses,  com- 
potes, all  forms  of  drinking  glasses  except  tumblers, 
and  many  larger  pieces  for  holding  fruits  or  desserts. 

Stemware 

Stemware  comprises  those  articles  which  consist  of 
a  bowl,  stem,  and  foot  or  base.  The  relative  size  of 
the  bowl  and  foot  is  determined  by  certain  rules  of 
proportion;  for  instance,  the  foot  must  be  neither  too 
small  nor  too  large  to  look  well  and  give  the  glass 
a  proper  balance.  The  stem  may  be  so  short  that  it  is 
scarcely  more  than  a  curve  between  the  two  larger  por- 
tions, or  it  may  hold  the  bowl  high  in  the  air. 

The  finer  grades  of  stemware  are  of  blown  glass,  and 
these  are  again  divided  into  those  in  which  the  stem 
is  "  drawn  '*  out  from  the  piece  composing  the  bowl, 
and  those  which  are  made  from  three  separate  gather- 
ings of  glass. 

71 


I 

it 


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GLASSWARE  DEPARTMENT 


Shaping  Stemware 

For  the  drawn  stems,  the  glassblower  gives  the 
bowl  its  general  shape  by  blowing  and  rolling,  or  shap- 
ing with  the  hand  tools ;  he  then  pulls  or  draws  out  a 
portion  of  the  soft  glass  until  it  forms  a  slender  stem. 
The  upper  picture  in  the  frontispiece  shows  the  stem 

being  formed.  . 

On  the  end  of  the  stem  another  bit  of  glass  is  then 
dropped,  flattened  out,  and  worked. 

If  the  glass  is  made  of  three  gatherings  the  bowl  is 
blown  into  a  mold ;  then  another  workman  drops  a  bit 
of  glass  on  the  bowl  and  shapes  a  third  piece  for  a 
foot,  which  is  then  flattened  and  shaped  as  in  the  drawn 

bowl. 

In  all  blown  glass  the  bubble  is  closed  over  the  top 
and  must  be  cut  away  with  shears  or  on  a  wheel.  The 
glass  is  then  reheated  and  the  edges  rounded  off.  The 
lower  picture  in  the  frontispiece  shows  the  finished 
piece  of  stemware  being  carried  to  the  lehrs. 

After  shaping  the  foot  the  soft  glass  is  attached  to  a 
glass  knob  or  pontil  called  a  "  punty,"  while  the 
"  boss,"  that  is,  the  shaped  or  rounded  top  of  the  bowl, 
is  being  removed. 

Variety  of  Shapes 

The  shapes  of  the  bowls  vary  widely.  The  principal 
ones  are: 


TABLEWARE 


73 


1.  Drawn,  usually  rather  pointed. 

2.  Straight-sided,  either  low  and  broad,  or  high 

and  narrow. 

3.  Ovoid,  or  rounded  like  an  tgg. 

4.  Bell-shaped,   with  sides  curving  in  and  wide 

mouth. 

These  are  only  the  general  types,  of  which  there  are 
many  variations. 

The  bowls  of  wine-glasses  are  usually  plain.  Gob- 
lets, compotes,  and  other  stemware  may  be  engraved, 
etched,  or  gilded. 

Stem  Variations 
Stems  may  be : 

1.  Plain  (straight  or  curved) 

2.  Twisted 

3.  Cut  or  "  bossed  ** 

Plain  stems  are  the  most  common. 

Twisted  stems  are  made  by  impressing  straight 
grooves  in  a  rod  of  viscous  glass  and  then  catching 
the  two  ends  and  twisting  them  to  give  a  spiral  effect ; 
or  by  fusing  glass  rods  or  canes  together  and  twisting 
them.  Color  is  sometimes  added  in  the  form  of  a 
twist  "  trailed  "  around  the  stem  on  the  outside. 

Cut  stems  may  be  cut  in  rings,  in  straight,  vertical 
lines,  in  spirals,  or  in  fine  patterns. 


1 


74 


GLASSWARE  DEPARTMENT 


The  foot  of  a  piece  of  stemware  is  not  perfectly 
flat,  but  hollowed  up  somewhat  in  the  middle.  It  may 
have  a  decoration  on  either  the  upper  or  the  under  side. 

Tumblers 

Thin  tumblers  are  blown  into  a  mold  and  the  top 
is  cut  off  in  the  same  manner  as  the  tops  of  stemware. 
Heavier  tumblers  are  usually  made  of  pressed  glass, 
though  the  finest  cut  tumblers  are  of  blown  lead  glass 
cut  on  wheels.  For  pressed  tumblers  the  glass  is 
poured  into  the  mold  and  pressed  by  the  metal  plunger. 
They  are  revolved  in  the  mold  while  cooling  in  order 
that  they  may  not  show  mold  marks.  The  molds  for 
this  purpose  are  lined  with  charcoal  or  a  similar  prepa- 
ration.    Pressed  tumblers  may  be  decorated  in  any  of 

the  usual  ways. 

If  the  mold  has  a  pattern  stamped  in  it  to  imitate 
cut  glass,  this  revolving  process  is  not  possible.  In 
this  case,  except  for  the  cheapest  grades,  the  mold 
marks  are  polished  off.  For  semicut  or  floral-cut  glass 
the  patterns  are  sharpened  and  finished  on  the  cutting 
wheels. 

Sets  for  Many  Purposes 

Many  articles  of  table  glass  are  sold  in  sets. 

A  water  set  consists  of  a  carafe,  bottle,  or  pitcher 
and  six  or  twelve  glasses  of  medium  size. 


TABLEWARE 


75 


Iced  tea  or  grape-juice  sets  consist  of  a  pitcher  and 
six  tall  glasses.     They  may  also  include  an  ice  tub. 

JVine,  cordial,  or  liqueur  sets  consist  of  a  decanter 
and  six  glasses.  Cordial  or  liqueur  glasses  are  very 
small,  holding  from  ^  to  i^/^  ozs.  Wine  glasses  hold 
from  2%  to  3  ozs.  Cocktail  and  champagne  glasses 
have  a  high  stem  and  a  shallow,  wide  bowl. 

Decanters  are  bottles  with  a  low,  broad  bowl  and  a 
slender  neck.  Decanters  for  liqueurs  are  small  and 
shaped  like  cruets  for  vinegar  or  oil. 

Water  bottles  or  carafes  are  stouter  than  decanters, 
and  are  usually  of  heavier  glass. 

Sherbet  sets  may  consist  of  six  or  twelve  glasses. 
The  stems  are  more  slender  than  those  of  wine  glasses 
and  the  bowls  shallower. 

Grapefruit  sets  consist  of  six  or  twelve  large  long- 
stemmed  glasses,  which  may  hold  either  the  half -fruit 
surrounded  with  cracked  ice,  or  a  smaller  glass  which 
contains  the  fruit  juice  and  is  set  in  the  ice. 

A  punch  or  lemonade  set  consists  of  a  large  bowl,  a 
ladle,  and  twelve  glasses,  often  set  on  a  plateau  or  a 
glass  tray. 

Finger-bowls  come  in  sets  of  six  with  or  without 
saucers. 

Berry  sets  consist  of  a  medium-sized  bowl  and  six 
berry  dishes. 

Coasters  for  use  on  a  polished  table  are  small,  flat 


1    i 


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76 


GLASSWARE  DEPARTMENT 


glass  discs  with  rims  for  holding  tumblers.  They 
come  in  sets  of  four  or  six. 

A  mayonnaise  or  a  whipped  cream  set  consists  of  a 
bowl,  spoon,  and  saucer. 

An  almond  or  a  relish  set  consists  of  a  small  fancy 
dish  and  six  very  small  side-dishes. 

Sugar  and  cream  sets  consist  of  a  small  pitcher  and 

a  bowl. 

A  flower  set  consists  of  a  large  vase  and  four  smaller 

vases. 

Bedroom  and  toilet  sets,  also  called  guest  or  boudoir 

sets,  consist  of  a  water  bottle  covered  with  a  small 

tumbler  fitting  closely  down  on  it. 

Toilet  bottles  for  medicines  are  of  two  standard 
sizes,  4  and  6  ozs.,  and  with  narrow  or  wide  mouths, 
according  to  the  material  which  they  are  intended  to 
contain.  The  plain  ones  are  of  clear  glass,  usually 
square,  with  the  name  of  the  material  they  contain 
marked  on  them  in  black  on  a  gold  background.  The 
more  elaborate  ones  are  decorated  in  enamels.  Such 
bottles  are  often  sold  in  sets  of  six  or  more,  and  may 
be  fitted  in  a  rack  ready  to  be  hung  in  the  bathroom. 

Single  Articles 

Many  single  articles  are  also  sold  in  the  Glassware 
Department. 


TABLEWARE 


77 


Pitchers  come  in  a  great  many  styles,  sizes,  and  de- 
signs. 

Tankards  and  jugs  are  both  a  form  of  pitcher,  the 
first  usually  high  and  slender  in  shape  and  the  latter 
low  and  broad.  Tankards  are  of  more  varied  and 
original  designs  than  pitchers  and  jugs  and  are  used 
for  more  special  purposes. 

Cruets  and  bottles  for  holding  dressing,  vinegar, 
catsup,  etc.,  differ  in  shape  and  size  according  to  their 
use.  All  of  them  have  stoppers;  cruets  have  handles 
also. 

Jars  are  wide  mouthed  and  may  be  low  or  high. 
Sometimes  they  are  squat,  small,  and  square,  though 
usually  they  are  round.  Sometimes  they  are  fitted 
with  a  glass  spoon  and  usually  with  stoppers  or  tops. 
Candy  jars  are  tall,  with  curving  sides  and  tops  fin- 
ished with  elaborate  handles  or  knobs. 

Glass  bowls  and  dishes  are  of  infinite  variety  in 
pressed,  molded,  or  cut  glass  and  with  every  type  of 
decoration.  Salad  bowls  are  low  and  broad  while 
fruit  bowls  are  high.  Rose  bowls  are  round  with  a 
small  opening  at  the  top. 

Ice  and  butter  tubs  are  tub-shaped  glass  dishes  with 
saucers. 

Compotes  or  sweetmeat  dishes  are  stemware  with 
flat  bowls  and  high  stems. 


78  GLASSWARE  DEPARTMENT 

Other  bonbon  dishes  are  set  flat  on  the  table,  and 
may  be  round,  oval,  or  of  any  fancy  shape. 

Casseroles,  cake,  pie,  and  bread  pans,  bean  pots 
ramekins,  and  other  kind  of  baking  dishes,  are  made  of 
glass  ovenware,  which  will  stand  a  high  temperature 
without  cracking.  (See  manual  on  "Housefurnish- 
ings  ")  These  articles,  when  fitted  into  any  standard 
mounting,  such  as  sterling  or  German  silver,  make 
attractive  dishes  from  which  to  serve.  Some  of  the 
higher-priced  pieces  are  decorated  with  light-cut  floral 
designs  and  sold  for  the  same  purpose  as  cut  glass 

serving  dishes. 

Glass  trays  have  wooden  or  metal  rims  and  may  be 
transparent  or  backed  with  silk,  cretonne,  inlaid  wood, 

etc. 


Chapter  IX 

MIRRORS  AND  TABLE  REFLECTORS 

Mirrors 

The  process  of  making  mirrors  has  radically  changed 
since  1835  when  J.  von  Liebig  invented  the  silver  ni- 
trate process.  Before  that  time  the  glass  was  backed 
by  amalgam,  a  mercury  compound. 

Amalgam  Mirrors 

The  silvering  of  an  amalgam  mirror  is  quite  an 
elaborate  process. 

First  a  thin  sheet  of  tin  foil  is  spread  out  on  a  table 
and  a  small  quantity  of  mercury  rubbed  over  it.  It  is 
then  carefully  cleaned  to  remove  dust.  On  this  founda- 
tion mercury  is  poured  until  it  is  about  a  quarter  of 
an  inch  deep  and  the  polished  glass  is  slid  over  the 
mercury.  Heavy  weights  are  placed  on  the  glass  and 
the  table  is  tilted  so  that  all  superfluous  mercury  will 
run  off.  After  a  period  of  twenty-four  hours  the 
weights  are  removed  and  the  glass  turned  with  the  sil- 
vered side  up  to  dry  and  harden. 

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GLASSWARE  DEPARTMENT 


Silvered  Mirrors 

The  real  silvering  of  glass  which  has  largely  taken 
the  place  of  the  amalgam  method  is  done  with  a  solu- 
tion of  silver  nitrate  and  ammonia.  The  silver  nitrate 
is  dissolved  in  an  equal  quantity  of  water,  and  ammonia 
is  added  to  it.  Then  a  very  small  quantity  of  potash 
and  more  ammonia  and  silver  nitrate  are  added. 

This  mixture  may  be  applied  in  two  ways— by  the 
hot  or  the  cold  process.  In  the  former  the  glass  is 
placed,  polished  side  up,  on  a  double  metallic  table 
heated  by  steam.  The  silver  solution  is  combined  with 
tartaric  acid  and  poured  over  the  heated  glass.  When 
dry  it  is  protected  by  a  coating  of  shellac,  copal  varnish, 
or  red  lead  or  is  electroplated  with  copper. 

Telescope  discs  are  silvered  by  the  cold  process.  In 
this  the  silver  nitrate  solution  is  combined  with  a  solu- 
tion of  sugar,  water,  and  alcohol.  The  disc  is  placed 
on  a  rocking  table  and  the  mixture  poured  on,  making 
a  thick  film.  The  water  is  allowed  to  remain  for  some 
time  until  the  deposit  has  settled.  The  mirror  is  then 
cleaned  with  alcohol  and  burnished  with  chamois  and 
jeweler's    rouge.     The    silvei;    forms    the    reflecting 

surface. 

The  amalgam  mirrors  are  more  permanent  than 
silver,  less  affected  by  sun,  heat,  and  dampness,  but 
the  mercury  fumes  ar^  very  bad  for  the  workmen. 


MIRRORS 


8i 


Platinum  Mirrors 

Platinum  mirrors  are  made  with  a  very  thin  film 
of  chloride  of  platinum  applied  with  a  brush  and  fired 
in  a  kiln.  They  are  grayish  in  color  and  are  chiefly 
used  in  fancy  boxes  and  similar  articles  because  of 
their  cheapness. 

Plateaux  or  Table  Reflectors 

Plateaux  are  plate  glass  mirrors  which  are  used  as 
bases  for  centerpieces,  punch-bowls,  or  other  table  fur- 
nishings for  decorative  effect.  They  add  greatly  to 
the  brilliancy  of  cut  glass  by  increasing  the  reflection 
of  light  from  its  many  facets. 

Plateaux  are  either  round  or  oval  and  range  from  8 
to  20  inches  in  diameter ;  the  larger  ones  are  used  for 
punch  sets  or  similar  purposes.  Some  reflectors  rest 
directly  upon  the  table;  others  are  raised  on  orna- 
mental feet  made  of  the  same  material  as  the  rim. 

The  outer  edge  of  the  glass  is  bevelled,  the  ridge 
being  usually  one-fourth  or  one-third  of  an  inch  wide; 
but  in  expensive  pieces  it  may  be  an  inch  or  more; 
sometimes  the  edge  is  cut,  engraved,  or  etched.  Serv- 
ing plateaux  have  a  rim  of  metal  raised  above  the  edge 
of  the  mirror  in  order  to  prevent  glasses  or  cups  from 
slipping  off. 

The  rims  of  these  table  reflectors  are  made  of  ster- 
ling silver  or  white  metal  silver-plated.     The  under 


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GLASSWARE  DEPARTMENT 


side  of  the  reflectors  is  covered  with  thick  paper,  felt, 
or  leather.  An  inner  lining  of  thick  cardboard  serves 
to  pad  the  glass  and  protect  it. 

Ancient  Mirrors 

Ancient  mirrors  were  of  metal — ^bronze  or  silver — 
though  some  glass  mirrors  were  coated  with  tin.  Glass 
mirrors  were  used  in  the  Middle  Ages  and  Venice  made 
them  on  a  commercial  scale  in  the  fifteenth  century. 


Chapter  X 

DESIGN  IN  GLASSWARE 

Fundamentals  of  Design 

In  designing  glassware  two  elements  must  be  consid- 
ered :  shape  and  decoration. 

Importance  of  Shape 

On  the  flat  surfaces  of  textile  materials  design  can 
be  expressed  only  in  pattern,  but  each  article  made  of 
glass  has  an  individual  shape  which  is  the  most  im- 
portant element  in  its  design. 

Many  people  who  make  and  handle  glass  do  not 
seem  to  appreciate  this  fact.  They  do  not  pay  any 
attention  to  form,  but  proceed  to  heap  decoration  upon 
ugly  and  awkward  pieces  in  order  to  make  them  beau- 
tiful. No  amount  of  decoration,  however,  can  do 
this.  It  often  only  emphasizes  the  ugliness  it  seeks 
to  conceal. 

The  beautiful  and  tractable  material  which  we  call 
glass  deserves  artistic  treatment  and  amply  repays  the 
artist  who  gives  it  his  most  careful  workmanship. 

83 


liil 


k 


h¥ 


84  GLASSWARE  DEPARTMENT 

But  the  fact  that  it  is  so  essentially  beautiful  has  made 
stupid  and  vulgar  designs  marketable,  whereas  if 
they  had  been  made  of  less  shining  material  no  one 
would  have  looked  at  them. 

Like  all  other  materials,  glass  is  most  beautiful 
when  treated  according  to  its  own  nature  and  not  made 
to  imitate  something  else.  Glass  made  by  the  Phoeni- 
cians and  the  Romans  was  molded  on  a  core  of  sand 
and  the  shapes  of  these  old  vessels  are  not  unlike  those 
made  of  pottery.  They  are  often  graceful  but  lack 
the  delicacy  which  we  associate  with  glass.  The  dis- 
covery and  perfection  of  the  art  of  glass-blowing  made 
possible  a  new  and  distinctive  form  of  art. 

Shapes  of  Cut  Glass  and  Blown  Glass  Articles 

Modern  glassware  may  be  divided  into  two  general 
groups :  heavy  and  substantial  pieces  whose  decoration 
is  cut  deeply  into  the  metal,  and  "  blown  glass  "  which 
is  shaped  by  the  expansion  of  air  and  finished  by  gentle 
manipulation  while  in  the  plastic  state. 

While  of  course  the  best  cut  glass  is  made  from 
blanks  which  are  blown  into  a  mold,  when  we  speak  of 
blown  glass  we  mean  the  thin  and  apparently  fragile 
types  which  show  that  they  have  had  delicate  handling. 

The  difference  in  process  determines  not  only  the 
shape  but  the  type  of  decoration  suitable  to  it. 

Heavy  cut  glass  is  made  in  simple,  well-proportioned 


DESIGN  IN  GLASSWARE 


85 


shapes,  and  depends  for  its  beauty  upon  the  jeweled 
effect  and  the  refraction  of  light  produced  by  the  deep 
cutting. 

The  shapes  of  blown  glass  pieces  may  be  simple 
also,  differing  but  little  from  the  lighter  kinds  of  cut 
glass,  but  on  the  other  hand  they  may  be  elaborate, 
and  so  delicately  fashioned  that  stems  or  handles  may 
be  easily  snapped  with  the  fingers.  Their  decoration 
should  be  correspondingly  dainty  and  fine. 

Purpose  for  which  Article  Is  to  be  Used 

The  shape  of  any  article  should  be  adapted  to  the 
purpose  for  which  it  is  to  be  used.  When  glass  is  in- 
tended for  practical  purposes  as  well  as  for  ornament, 
those  purposes  should  be  given  careful  consideration. 

Pitchers  are  made  to  hold  liquids.  They  should 
therefore  be  well  balanced  so  that  they  cannot  be  easily 
overturned.  The  handle  should  be  so  constructed  that 
the  pitcher  will  tip  at  a  convenient  angle  and  the  spout 
or  lip  so  shaped  that  the  contents  of  the  pitcher  will 
pour  through  it  and  not  over  its  edges. 

Stemware  for  drinking  glasses  should  have  stems 
which  may  be  comfortably  and  securely  handled.  The 
ridges  on  heavy  glasses  are  partly  for  this  purpose, 
but  light  wine  glasses  do  not  need  such  aids.  The 
bowls  of  drinking  glasses  are  also  shaped  according 
to  their  use. 


II 


GLASSWARE  DEPARTMENT 


86 

The  shapes  of  large  bowls  and  flat  dishes  should  be 
determined  in  part  by  the  kind  of  food  or  drmk  wh.ch 

thev  are  to  contain. 

Vases  are  of  many  shapes  because  flowers  reqmre 

different  settings.     Roses  and  violets.  I'''"  J^^^^; 
tions  cannot  be  properly  arranged  m  vases  of  the  same 

*  Traditional  shapes  for  glassware  are  usually  good 
but  they  may  easily  be  vulgarized  by  the  change  °f  a 
curve,  the  shortening  of  a  stem,  or  the  add  t,on  of 
some  meaningless  detail.  Only  the  practjce  o  tudj. 
ing  pieces  which  are  known  to  be  beautiful  will  tram 
Z  eye  so  that  it  will  recognize  beautiful  hnes  and 
forms. 

Designs  for  Cut  Glass 

As  the  blanks  for  cut  glass  must  be  thick  enough  to 
stand  the  pressure  and  the  grinding  of  the  wheels,  they 
naturally  have  a  somewhat  massive  appearance^ 

Old  English  cutters  increased  th,s  massive  effect  by 
the  simple  shapes  of  their  glassware  and  the  straight 
Hnes  of  the  miter  or  hobnail  patterns.  The  pieces  m 
Figure  8  are  fine  representatives  of  this  type  of  cutting^ 
Notice  the  curving  lines  sweeping  upward  over  Ae 
shoulder  of  the  vase  and  the  dignity  m  each  of  the 
shapes. 


*-'"«^-»i' 


■    M    KtLJ 


'"^r. 


, 


Courtesy  of  A.  Gredelue 
Figure  8.     Patterns  in  Miter  Cutting 


'  / 


ii 


DESIGN  IN  GLASSWARE 


87 


The  miter  cuttings  are  either  faceted  like  jewels  or 
molded  in  simple  blunt  designs. 

The  American  floral  cuttings  are  of  several  kinds. 
Some  of  them  are  as  deep  as  miter  cuttings  and  require 
a  heavy  blank,  while  others  are  shallow  enough  to  re- 
semble etching  or  engraving.  The  deep  floral  cuts 
are  also  combined  with  miter  cuts  or  with  light  frosted 
floral  designs. 

In  order  to  conform  to  the  general  laws  of  design, 
great  care  must  be  taken  to  adapt  the  cutting  to  the 
shape  and  purpose  of  the  piece  of  glass  to  be  decorated. 
For  example,  the  cutting  on  the  lip  of  a  jug  or  pitcher 
should  be  in  lines  radiating  from  its  base  to  the  edge. 
They  should  never  cut  across  it.  This  applies  also  to 
cutting  in  the  handle  which  should  either  be  spiral 
(suggesting  a  continuous  line)  or  follow  the  curve  of 
the  handle  even  more  closely. 

Sprays  of  flowers  or  leafage  springing  from  the 
straight  line  at  the  base  of  a  bowl  or  pitcher  are  abrupt 
and  awkward,  while  an  upright  conventional  pattern  is 
satisfying. 

A  branching  spray  may  be  graceful  when  it  appears 
to  start  from  the  stem  of  a  goblet,  especially  if  it  fol- 
lows the  general  line  of  the  glass. 

In  some  designs  the  cuttings  are  so  deep  as  to  break 
completely  the  outline  of  the  piece  and  make  it  appear 
ready  to  fall  apart. 


|i 


m 


88  GLASSWARE  DEPARTMENT 

Another  defect  is  found  in  the  use  of  patterns  in 
straight  bands  which  cross  the  article  at  any  angle  and 
even  stop  abruptly  in  the  middle  of  a  side.  Stra.gh 
lines  are  needed  to  steady  a  pattern,  whde  curved  lines 
give  it  grace  and  lightness.  Such  bands  of  ornament, 
however,  are  always  noticeable  and  because  they  are 
stiff  and  aggressive  they  should  follow  the  outhne  of 
the  piece  like  a  border.  When  they  run  all  oyer  the 
side  they  look  like  bands  of  embroidery  trimming  out 

°^^nd"idual  cuttings  should  be  proportioned  to  the 
size  of  the  article.  A  single  flower  should  not  cover 
the  whole  side  of  a  pitcher  or  vase  and  a  star  should 
not  look  like  a  rising  sun.  Small  patterns  usually  give 
a  more  artistic  effect,  but  they  should  not  be  so  cut 
up  with  crossing  lines  as  to  look  confused. 

Standard  Cut  Glass  Patterns 

Among  many  admirable  patterns  in  cut  glass  are: 
Colonial  designs  with  simple  geometrical  divisions 

following  the  outline  of  the  article. 
Small  separate  designs  repeated  on  a  plain  or 

"  mat "  background. 
Light  floral  cuttings  usually  much  conventional- 
ized and  sometimes  frosted. 
Old  English  miter  and  hobnail  patterns. 


il 


DESIGN  IN  GLASSWARE 


89 


Some  combinations  of  miter  and  floral  patterns  are 
effective  but  they  must  be  treated  with  care.  They  are 
successful  only  if  the  flowers  are  so  conventional  as  to 
become  a  part  of  the  miter  pattern,  or  if  the  miter  pat- 
tern is  so  unobtrusive  as  to  form  a  background  or 
frame  for  the  flowers.  If  the  stiff  lines  of  miter  cut- 
ting are  alternated  with  sprays  of  flowers  so  that  each 
form  of  cutting  is  thrown  into  relief,  all  unity  of  de- 
sign is  lost. 

Engraved  Glass  Patterns 

While  deep  cutting  gives  glass  the  brilliancy  of 
jewels,  the  designs  are  restricted  to  formal  and  con- 
ventional patterns.  Light  floral  cutting  is  a  freer 
form,  and  engraving  or  etching  may  be  given  infinite 
variety  because  it  is  essentially  a  surface  decoration. 

In  criticizing  the  patterns  in  engraved  glass  we  need 
not  consider  the  hard  material  or  the  difficulties  of 
workmanship ;  we  ask  only  for  graceful  outlines,  clear- 
ness, unity,  and  suitability.  The  greater  freedom 
which  is  given  to  a  designer  of  engraved  glass  does 
not,  however,  release  him  from  the  laws  which  govern 
all  design  or  pattern-making. 

Laws  of  Design 

Some  of  these  laws  may  be  stated  simply.  First 
the  elements  of  a  pattern,  that  is,  the  figures,  are 
either : 


90  GLASSWARE  DEPARTMENT 

Natural  —  imitating  nature  as  much  as  the  mate- 
rial will  permit. 

Conventional  —  suggesting  nature  but  simplified 
and  adapted  to  the  purpose  of  the  decoration  or 
the  pattern. 

Abstract  —  made  up  of  repeated  lines  and  pat- 
terns which  have  no  intentional  resemblance  to 
natural  forms.  ( Sometimes  it  is  hard  to  draw 
a  clear  line  between  very  much  conventionalized 
nature  and  abstract  patterns.) 

Elements  of  Design 

Pattern  designs  are  made  up  of  lines,  forms,  and 
spaces. 

I.  There  must  be  a  center  of  interest.  In  a  stand- 
ing piece  of  glassware  this  should  usually  be  at  a  point 
a  little  above  the  middle  of  the  article.  In  a  bowl  or 
flat  piece  it  is  either  in  the  middle  or  at  the  handle  end. 
The  pattern  may  radiate  from  this  point  or  it  may  only 
be  given  a  little  more  emphasis  there. 

In  the  case  of  simple  borders  or  of  repeated  all-over 
patterns  the  shape  of  the  article  is  made  the  center  of 
interest  to  which  the  pattern  calls  attention. 

If  the  pattern  starts  from  the  base  as  in  many  gob- 
lets, pitchers,  and  vases,  the  plain  upper  part  is  still 
a  part  of  the  design  and  is  thrown  out  in  relief  like 


f 


DESIGN  IN  GLASSWARE 


91 


the  broad  petals  of  flowers  springing  out  of  the  more 
complicated  cup  or  calyx. 

2.  The  pattern  should  be  well  distributed  and  have 
a  proper  balance.  This  is  especially  important  if  the 
pattern  is  repeated  a  number  of  times,  as  a  balance 
good  enough  for  a  single  composition  may  not  be  good 
enough  for  repetition. 

3.  The  parts  of  a  design  must  harmonize  and  be 
well  bound  together.  The  crossing  of  a  design  from 
one  part  of  a  piece  having  several  sections  to  another 
is  always  effective.  For  example,  the  extension  of 
the  pattern  from  the  stem  to  the  bowl  of  stemware  or 
from  the  handle  to  the  body  of  a  jug  or  pitcher  gives 
a  sense  of  unity  and  pleasure. 

Certain  other  principles  of  design  contribute  to  the 
beauty  of  a  pattern.     Some  of  these  are : 

Gradation,  by  which  repeated  forms  vary  in  size. 

Symmetry  and  contrast,  by  which  the  design  is 
given  unity  and  variety. 

Radiation,  which  gives  the  eye  a  sense  of  com- 
pleteness. In  nature  flowers,  wings,  and  shells 
all  have  these  beautiful  radiating  lines. 

Composition  of  line,  which  is  the  term  given  to 
the  arrangement  of  lines  so  that  they  flow  into 
one  another;  and  even  when  the  ends  of  the 
lines  do  not  connect,  the  eye  is  guided  by  their 
general  direction  to  the  points  of  interest. 


■I 


92 


GLASSWARE  DEPARTMENT 


Good  Design 

In  judging  the  different  types  of  decoration,  certain 
guiding  principles  should  be  recognized. 

The  decoration  should  be  suitable  to  the  material  and 
to  the  manner  in  which  it  is  worked. 

Decoration  should  add  interest  to  the  article  deco- 
rated. It  should  be  appropriate  to  the  purpose  of  the 
article.  The  artist  should  always  strike  a  balance 
between  use  and  beauty.  Very  elaborate  decoration  is 
better  suited  to  articles  that  are  intended  only  for 
ornament  than  to  those  which  are  to  be  given  hard 
daily  use. 

Decoration  should  always  bear  a  direct  relation  to 
the  structural  lines,  that  is,  to  the  shape  of  the  article. 
The  pattern  should  either  follow  those  lines  or  bring 
out  their  beauty  by  contrast 

The  Use  of  Color  in  Design 

The  principles  of  design  which  apply  to  cut  and 
engraved  glass  are  no  less  important  when  the  decora- 
tion is  in  gold,  silver,  or  colored  enamel.  Patterns 
which  are  given  emphasis  by  any  of  these  means 
should  be  even  more  carefully  designed  than  those 
which  are  less  noticeable. 

Nothing  is  in  poorer  taste  than  a  cheap  and  tawdry 
design  worked  out  in  heavy  gold  or  colored  figures. 

Old  Venetian  glass  is  the  best  example  of  elaborate 


DESIGN  IN  GLASSWARE 


93 


designs  produced  by  the  use  of  color.  Its  stripes  and 
figure  patterns,  festoons,  and  lace-work  show  the  mar- 
velous possibilities  of  the  plastic  material.  Some  of 
these  elaborate  designs,  however,  are  not  beautiful  but 
merely  curious.  Modern  Venetian  glass  has  fewer 
varieties  and  American  copies  of  this  glass  are  still 
simpler,  having  much  less  grace  and  delicacy  of  out- 
line. This  is  due  in  part  to  the  greater  hardness  of 
the  metal  of  American  glass  and  in  part  to  the  greater 
haste  in  production  which  leaves  the  workman  no  time 
for  individual  treatment  of  his  material. 

When  colored  glass  is  transparent  or  translucent  it 
has  a  unique  beauty  which  requires  the  most  sympa- 
thetic treatment. 


ill 


Part  III— Decorative  Glass 


Chapter  XI 

METHODS  OF  DECORATION 

Possibilities  of  Glass 

Glass  is  a  material  with  almost  unlimited  possibili- 
ties for  the  making  of  beautiful  things.  As  we  have 
seen,  it  may  be  blown,  cut,  or  molded  into  the  most 
exquisitely  graceful  shapes,  while  its  transparency, 
crystal  clearness,  and  bright  surface  make  it  second 
only  to  the  diamond  in  its  reflection  of  light  and  the 
prismatic  colors  which  it  scatters. 

In  nearly  all  its  forms  glass  is  more  or  less  orna- 
mental, and  attempts  are  usually  made  to  give  even  the 
commonest  articles,  such  as  bottles,  glass  mugs,  or 
pitchers,  a  graceful  shape  and  some  kind  of  decora- 
tion. Most  exquisite  effects  are  produced  with  glass, 
moreover,  in  the  hands  of  the  true  artist.  Among  the 
priceless  treasures  of  ancient  and  modern  times  may 
be  found  many  specimens  of  beautiful  glass. 

95 


^i   I 


96  GLASSWARE  DEPARTMENT 

Colored  Decoration  of  Glass  Surfaces 

The  various  methods  of  decorating  the  surface  of 
glass  are : 

Gilding 

Painting  and  enameling 

Lacquering 

Gilding 

Gilding  is  an  old  form  of  glass  decoration.  It  is 
done  by  the  application  of  gold-leaf,  liquid  gold,  or 
bronze  powder.     There  are  three  methods  of  gilding : 

Gold  resist 
Gold  banding 
Application  of  gold-leaf 

Gold  Resist 

The  gold  resist  method  is  a  combination  of  etching 
and  gilding,  as  the  design  is  first  eaten  out  by  the  acid 
and  then  filled  with  gold.  The  piece  is  fired  to  unite 
the  gold  with  the  glass,  and  the  design  is  burnished 
with  a  hard,  smooth  stone  for  a  bright  finish,  or  with 
spun  glass  or  fine  sand  for  a  dull  finish.  The  gold 
may  be  what  is  called  "  liquid  bright "  gold,  which  is 
gold  bullion  melted  down  in  an  acid  so  that  it  may  be 
applied  with  a  brush. 


METHODS  OF  DECORATION 


97 


Gold  Banding 

Gold  banding  is  more  simple  than  the  gold  resist 
method.  It  may  be  done  with  the  same  gold  solutions, 
or  a  cheaper  bronze  powder  may  be  used.  The  arti- 
cle to  be  banded  is  placed  on  a  revolving  disc,  and  the 
workman  applies  the  solution  with  a  brush  as  it  turns 
before  him.  Banding  may  also  be  done  by  machine. 
The  gold  is  burnt  in  and  burnished  as  with  the  resist 
method. 


I 


Gold-leaf 

Gold-leaf  is  gold  beaten  out  extremely  thin.  It  may 
be  reduced  to  ^50,000  of  an  inch  in  thickness.  It  was 
formerly  used  for  gilding  but  is  now  replaced  by  the 
two  other  methods.  The  gold  leaf  was  attached  to 
the  glass  by  means  of  thin  wax  or  glue  and  fired  until 
it  became  fused  upon  the  glass. 

Painting  and  Enameling 

Enameling  is  decorating  glass  with  color  by  means 
of  designs  painted  by  hand  in  opaque  glazes  or  enamels 
which  unite  with  the  glass  when  fired.  The  name  is 
also  given  to  a  method  of  transferring  printed  patterns 
made  of  these  materials  to  the  glass  by  pasting  them 
on  and  then  firing  the  piece. 


■*A 


98 


GLASSWARE  DEPARTMENT 


Lacquering  or  Japanning 

This  is  done  in  the  same  way  with  cheaper  materials 
mixed  with  shellac  or  varnish  and  baked  on  the  sur- 
face. It  is  an  inexpensive  and  showy  form  of  glass 
decorating. 

Silver  Deposit  Glass 

A  very  pleasing  division  of  the  Glassware  Depart- 
ment is  the  silver  deposit  glass,  which  is  found  in 
vases,  water  sets,  wine  sets,  and  other  articles.  The 
chief  decoration  is  silver,  which  is  overlaid  upon  it  in 
graceful  patterns.  The  foundation  is  of  plain  glass 
and  sometimes  has  fine  stone  cutting  covering  the  space 
which  is  not  silvered. 

Process  of  Manufacture  of  Silver  Deposit  Ware 

The  blanks  for  the  silver  deposit  ware  are  designed 
to  fit  the  decoration  which  is  to  be  applied  and  are 
made  to  order  in  large  quantities  for  the  cut  glass 
factories. 

The  process  of  manufacture  from  these  blanks  con- 
sists of: 

Sketching  the  pattern 

Firing  the  design,  to  form  the  base  for  the  silver 

Electroplating 

Polishing 

Engraving 


\r  t 


METHODS  OF  DECORATION  99 

Sketching  the  Pattern 

The  designer  outlines  the  decoration  on  the  blank 
with  either  a  brush  or  a  stencil  pattern.  The  material 
used  for  making  the  design  is  a  metallic  silver  solution 
composed  of  silver  99.9  per  cent  pure,  nitric  acid,  and 
other  chemicals.  It  is  a  dark  gray  substance  of  the 
consistency  of  thick  paint.  The  coating  is  allowed  to 
dry  before  the  next  or  firing  process. 

Firing 

The  pieces  are  arranged  on  shelves  in  the  kiln  and 
the  fire,  usually  of  gas,  is  lighted.  The  temperature 
is  gradully  raised  to  1200°  C,  a  cherry  red  or  white 
heat.  This  takes  two  hours  or  more;  the  whole 
process  of  raising  and  lowering  the  temperature  re- 
quires about  four  hours.  During  the  process  of  firing 
the  metal  of  the  design  melts  and  unites  with  the  glass, 
which  has  also  been  softened  by  the  heat.  The  design 
is  white  when  it  comes  out  of  the  furnace  and  is  the 
surface  for  electroplating. 

Electroplating 

After  the  pieces  have  cooled  to  a  normal  tem- 
perature they  are  suspended  on  copper  or  brass  rods  in 
a  tank  filled  with  a  solution  of  nitrate  of  silver.  The 
rods  are  connected  with  the  negative  pole  of  a  mag- 


lOO 


GLASSWARE  DEPARTMENT 


neto-electric  machine.  On  rods  in  the  center  of  the 
tank  are  suspended  bars  of  silver  99.9  per  cent  pure, 
connected  with  the  positive  pole  of  the  machine. 

A  current  of  electricity  passed  through  the  solution 
causes  the  tiny  particles  of  silver  in  solution  to  arrange 
themselves  on  the  metallic  surface  of  the  design.  The 
rest  of  the  glass  is  unaffected  by  the  process  as  the 
silver  will  attach  itself  only  to  the  metallic  surface. 

The  pieces  are  left  in  the  solution  from  1%  to  24 
hours,  according  to  the  desired  thickness  of  the  de- 
posit. Sometimes  a  thin  band  is  deposited  and  some- 
times a  heavy  coat  suitable  for  engraving  or  cutting. 
For  ware  of  the  best  quality  the  silver  deposited  by  the 
electroplating  process  is  also  99.9  per  cent  pure.  The 
design  is  still  white  when  it  is  removed  from  the  tank 
and  remains  so  until  it  is  polished. 

Sometimes  a  colored  background  is  produced  by 
covering  the  inside  of  the  article  with  a  colored  enamel 
and  firing  the  piece  again.  A  backing  of  gold  may  be 
applied,  which  makes  the  design  silver  on  one  side  and 
gold  on  the  other. 

Polishing 

The  polishing  process  is  in  two  parts. 

First  the  workman  holds  the  piece  against  a  rapidly 
revolving,  coarse,  buffing  wheel  made  of  canton  flannel 
softened  by  grease.     This  cuts  down  and  smoothes  the 


METHODS  OF  DECORATION 


lOI 


surface  of  the  silver.  The  tiny  particles  which  are 
rubbed  oflF  by  the  wheel  are  collected  by  suction  and 
purified  for  later  use.  This  process  is  called  surface 
buffing. 

The  second  buffing  is  given  with  a  softer  buffing 
wheel  covered  with  rouge.  This  gives  the  silver  a 
high  luster. 

Engraving  the  Silver  Deposit 

There  are  two  methods  of  brightening  the  design  or 
adding  to  the  delicacy  of  its  detail.  True  engraving 
is  done  in  the  same  way  as  other  engraving  on  silver 
or  gold,  with  delicate  tools  and  most  careful  workman- 
ship. The  deposit  must  be  reasonably  thick  and  not 
too  hard  for  the  purpose.  Engraving  on  silver  de- 
posit requires  great  care  because  of  the  brittle  glass 
background. 

The  other  process  is  known  as  imitation  engraving. 
In  this  the  workman  scratches  away  the  metallic  silver 
of  the  sketched  design  with  needles  of  varying  degrees 
of  fineness.  When  the  piece  is  electroplated  the  silver 
is  not  deposited  along  the  lines  thus  scratched.  The 
true  engraving  is  distinguished  from  the  imitation  by 
the  delicacy  and  accuracy  of  line. 

Original  Process 
This  artistic  and  popular  form  of  decorated  glass 


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originated  in  France  where  the  process  was  at  first 
very  elaborate  and  costly.  The  piece  of  glass  was  first 
coated  with  a  suitable  chemical  to  make  the  metal  ad- 
here to  the  glass  and  then  electroplated  with  silver  all 
over.  The  silver  was  then  cut  away  from  the  design 
with  hand  tools.  This  early  method,  with  some  im- 
provements, was  followed  until  the  present  one  was 
invented. 

Meaning  of  the  Term  "  Art  Glass  " 

All  glass  which  has  been  given  graceful  form  and 
artistic  decoration  might  be  included  under  the  title 
**  art  glass,"  but  that  which  is  cut,  engraved,  or  orna- 
mented with  gold  or  silver  is  usually  classed  under 
those  heads. 

The  name  art  glass  is  generally  applied  to  glass 
which  is  artistic  not  only  in  shape  and  design  but  is 
remarkable  also  for  its  beautiful  color  or  mixture  of 
colors.  Sometimes  the  color  is  fused  on  the  outside 
after  the  piece  is  formed ;  but  in  the  most  characteris- 
tic forms  —  the  Venetian,  Bohemian,  and  Tiffany 
glass  —  the  color  is  introduced  into  the  molten  glass. 

Expert  chemists  are  constantly  at  work  discovering 
new  combinations  and  methods  of  treatment  which 
will  produce  new  color  effects.  If  two  coloring  oxides 
are  used  together,  their  union  produces  a  new  color 
which  .may  not  resemble  either;  by  the  multitude  of 


METHODS  OF  DECORATION 


103 


these  combinations  the  color  scale  of  glass  is  rendered 
almost  endless. 

Colored  Glass 

Some  of  the  popular  forms  of  art  glass  are  known 
under  names  denoting  their  color  or  their  distinguish- 
ing quality,  as : 


Amber 

Wisteria 

Mulberry 

Green 

Opaline  or  opal 

Moonlight  iridescent 

Verre  de  soie 

Pearl  luster 

Calcite 


Mahogany 
Black 
Dark  blue 
Rose 

Cream-colored 
White 

Metallic  luster 
Gemmed  or  sealed 


Stained  glass 

Amber  glass  is  a  clear  brownish-yellow.  It  is  found 
in  tableware  such  as  sherbet  cups,  thin  wine  glasses, 
and  ornamental  pieces,  and  also  in  vases  of  various 
shapes. 

Wisteria  or  mulberry  glass  is  a  rich  but  somber  pur- 
ple which  has  become  popular  recently.  It  is  used 
almost  entirely  for  decorative  glass. 

Green  glass  is  attractive  even  in  an  inexpensive 
quality  and  is  much  used  for  vases  and  fern  dishes. 

Opaline  or  opal  glass  has  a  shimmering  changeable 


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effect,  caused  by  the  application  of  metallic  oxides  to 
the  surface  of  the  glass.  It  is  known  as  moonlight 
iridescent,  verre  de  soie,  pearl  luster,  and  calcite. 

Moonlight  iridescent  is  a  transparent,  faintly  opaline 
glass  resembling  the  old  Bohemian  in  its  play  of  color. 

Verre  de  soie  is  a  French  glass  almost  transparent 
but  slightly  milky  with  a  delicate  pearly  luster  sug- 
gestive of  silk.  It  is  called  plain  when  of  a  pure  white 
satiny  finish  or  when  only  faintly  opalescent.  The 
colors  are  soft,  pale  lavender,  green,  and  blue.  It  is 
often  engraved  with  a  light  cutting. 

Pearl  luster  is  similar  to  Verre  de  soie,  but  is  heavier 
and  of  less  delicate  colors.  It  is  also  more  opaque. 
The  pieces  are  often  decorated  with  gold  banding  or 
designs  etched  in  gold. 

Calcite  is  a  brilliantly  opalescent,  opaque  glass  sug- 
gesting the  more  gorgeously  colored  Tiffany  glass. 
The  outside  is  creamy  white  and  the  inside  has  a  beau- 
tiful play  of  warm  yellow,  orange,  green,  and  purple. 

Mahogany  glass  is  one  of  the  most  recent  popular 
forms  of  colored  glass.  It  is  made  in  flower  bowls, 
fern  dishes,  vases,  candlesticks,  and  other  articles  of 
decorative  ware,  either  plain  or  ornamented  with  gold 
and  silver.  The  glass  is  a  deep  brown  or  mahogany 
color  with  wavy  lines  to  imitate  wood  graining. 

Black  glass  has  had  a  vogue  which  is  hard  to  under- 
stand, as  it  is  inappropriate  for  table  decoration  and  is 


METHODS  OF  DECORATION 


105 


at  all  times  a  somber  background  or  setting  for  flowers. 
The  funereal  effect  is  somewhat  lightened  .by  deco- 
rations of  bright  colored  flowers,  but  its  popularity  will 
not  last  after  the  novelty  has  worn  off  because  it  has 
few  of  the  characteristics  which  give  glass  its  beauty 
and  charm. 

Dark  blue,  rose,  and  deep  cream-colored  glass  may 
be  seen  in  a  large  number  of  decorative  pieces,  some  of 
which  are  very  dainty  and  soft  in  tone. 

White  glass  is  often  ornamented  with  lines  or  bands 
of  color  and  color  is  put  on  in  the  trailed  decorations, 
handles,  and  finishing  touches.  In  these  cases  the 
added  colored  glass  is  previously  prepared  in  the  form 
of  short  rods,  which  are  reheated  and  applied  as  the 
design  requires. 

Metallic  lusters  may  be  produced  by  placing  par- 
ticles of  metal  on  the  glass  and  fusing  them  into  it. 
The  fumes  of  stannous  oxide  will  give  glass  an  arti- 
ficial iridescence  by  coating  it  with  a  thin  layer  of 
metallic  tin. 

Gems  or  seals  are  made  by  dropping  molten  glass  on 
the  v^essel  while  it  is  still  soft  and  pressing  it  with 
metal  seals. 

There  is  only  one  real  stain  for  glass,  which  is  called 
"silver  stain"  (see  Chapter  XVII).  The  term  is 
applied  to  glass  which  is  either  colored  in  the  batch 
with  "pot  metal"  color  or  painted  with  enamel  colors 
for  windows. 


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GLASSWARE  DEPARTMENT 


Flashed  Glass 

Flashed  glass  is  made  by  placing  a  very  thin  layer 
of  deep  ruby-colored  glass  upon  the  surface  of  a  sheet 
of  colorless  glass  of  ordinary  thickness.  This  is 
done  by  mixing  the  two  kinds  of  glass  in  one  gather- 
ing which,  when  blown,  produces  this  effect.  Other 
colors  are  also  used  for  the  flashed  glass  process, 
though  ruby  red  is  the  most  common.  Flashed  glass 
may  always  be  detected  by  looking  closely  at  the  edge 
of  the  sheet,  when  the  thin  layer  of  color  is  plainly 
evident.  It  is  in  reality  a  veneer  of  color  laid  upon 
one  side  of  a  sheet  of  glass  and  may  be  removed  in 
many  cases  by  an  acid  or  an  abrasion.  Flashed  glass 
with  several  layers  of  different  colors  opens  up  a  won- 
derful field  to  the  decorator  and  the  cutter. 


Chapter  XII 
VENETIAN  AND  BOHEMIAN  GLASS 

Beauty  of  Design  and  Coloring  in  Venetian  Glass 

In  the  section  of  the  department  devoted  to  art 
glass,  pieces  of  Venetian  glass  immediately  attract 
attention  because  of  their  daintiness,  faint,  delicate 
coloring,  and  artistic  designs.  Some  seem  to  be 
scarcely  more  than  thin  brilliant  bubbles  of  glass; 
others  are  more  solid  but  with  strange  lines,  twists, 
and  flutings  of  color  which  have  been  introduced  ap- 
parently by  magic. 

For  the  table  there  are  decanters,  glasses,  cups, 
plates,  finger-bowls,  and  many  varieties  of  compotiers, 
bonbonnieres,  and  baskets  for  holding  fruit  or  flowers. 
For  the  toilet  table  are  scent  bottles,  powder  boxes,  and 
other  dainty  accessories ;  while  urns,  candlesticks,  and 
innumerable  vases  seem  designed  for  beauty  alone 
rather  than  for  any  sort  of  use.  Among  other  fanci- 
ful decorations  may  usually  be  found  reproductions  of 
natural-colored  fruit  in  thin,  transparent  glass. 

Venetian  glass  has  been  celebrated  for  more  than 

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a  thousand  years  for  its  graceful  and  delicate  shapes 
and  beautiful  coloring.  Though  the  industry  has  died 
down  several  times,  it  has  been  revived  again  and 
again.  It  flourishes  today  on  the  Island  of  Murano, 
from  whence  importations  have  been  regularly  ob- 
tained by  merchants  who  carry  fine  lines  of  glassware. 

Composition 
Venetian  glass  is  composed  of: 

Silica 
Soda 
Lime 
Potash 

It  lacks  the  brilliancy  of  lead  glass,  but  its  colors 
are  exceedingly  soft  and  beautiful  and  its  luster  is 
very  deep  and  permanent.  This  luster  is  the  result  of 
many  reheatings,  some  pieces  being  put  into  the  fur- 
nace as  many  as  fifty  times.  It  is  highly  fusible  and 
therefore  may  be  blown  very  thin  and  is  readily 
molded  into  artistic  shapes.  It  is  also  very  light  and 
fragile,  though  if  reheated  many  times  it  becomes 
tougher  than  it  appears  to  be. 

Curious  Shapes 

The  old  Venetian  workmen  made  many  fantastic 
shapes,  such  as  drinking  glasses  which  resembled  ships, 


VENETIAN  AND  BOHEMIAN  GLASS        109 

whales,  lions,  or  birds.  Modem  manufacture  is  less 
grotesque,  but  birds  and  fruits  are  common  forms  of 
decoration.  The  dragon  is  a  favorite  figure  always, 
showing  perhaps  a  strong  Oriental  influence. 

The  materials  in  Venetian  glass  are  seldom  pure, 
and  it  is  therefore  apt  to  have  a  faint  tinge  of  yellow; 
or  if  manganese  has  been  added  to  neutralize  the  iron, 
it  has  a  faint  purplish  hue. 

The  Venetian  glassmaker  is  an  artist  as  well  as  a 
skilled  artisan.  As  he  stands  before  the  working  hole 
of  his  furnace,  blowing  his  airy  bubbles,  tossing  them 
up  and  down,  and  twisting  and  fashioning  the  delicate 
stems  and  handles,  he  gives  each  piece  an  individuality 
and  charm  which  can  be  achieved  only  as  the  result  of 
affectionate  care  and  pleasure  in  his  work. 

Process  of  Formation 

In  making  a  vase,  the  body  is  first  blown  and  then 
the  piece  is  shaped  to  form  the  foot.  It  is  reheated 
and  the  neck  widened  and  shaped;  the  tube  for  the 
handle  is  formed  and  fastened  to  the  body;  and  it  is 
again  heated  and  given  its  final  form.  It  may  have 
a  coil  of  glass  around  it  from  which  the  head  of  a 
dragon  is  deftly  molded;  or  fruits  and  flowers  of 
colored  glass  may  be  fused  on,  as  the  handle  and  foot 
have  been. 


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GLASSWARE  DEPARTMENT 


An  interesting  feature  of  Venetian  glass  is  the  in- 
troduction of  color  in  fine  lines  or  spirals  which  seem 
to  be  embedded  in  some  miraculous  way  in  the 
material.  The  process  is  complicated,  but  not  hard  to 
understand. 

Rods  or  "  canes  "  of  glass  are  made  first  by  dipping 
the  blowpipe  into  colored  glass,  drawing  it  out,  mar- 
vering  it  into  a  cylinder  2  or  3  inches  in  length,  and 
then  dipping  this  glass  cylinder  into  clear  glass,  which 
forms  a  coating  all  over  it.  This  cane  is  2  or  3  inches 
in  diameter,  and  as  broad  as  it  is  long,  when  the 
process  of  drawing  is  begun. 

One  workman  holds  the  end  of  the  cane  on  his  blow- 
pipe, while  another  grasps  the  other  end  and  walks 
slowly  away,  drawing  it  out  until  it  is  420  yards  in 
length  and  ^/^5  inch  in  diameter,  with  a  thin  thread  of 
color  in  the  middle.  In  some  cases  the  colored  thread 
is  wound  around  a  rod  to  make  a  spiral  before  it  is 
dipped  in  the  clear  glass,  but  the  drawing  out  is  the 
same.  These  canes  are  cut  with  shears  in  desired 
lengths  and  may  be  used  in  various  ways.  For  a 
vase  the  canes  may  be  placed  side  by  side  to  line  a 
mold,  and  a  thin  glass  coating  blown  in  the  center  to 
tmite  them.  The  piece  is  then  reheated  in  the  fur- 
nace and  worked,  and  finally  is  cut  off  with  pincers 
which  press  the  canes  together  at  that  point. 


f 


VENETIAN  AND  BOHEMIAN  GLASS         III 


Filigree  Glass 

A  filigree  glass  called  reticelli  is  made  by  placing 
side  by  side  a  series  of  transparent  rods  or  canes,  each 
containing  a  twisted  thread  of  colored  or  milk-white 
glass.  The  rods  are  then  heated  until  they  are  fused 
into  a  single  sheet  of  glass  with  a  ribbed  surface. 
Two  sheets  made  in  this  way  are  laid  across  each  other, 
slanting  so  that  a  small  air  space  is  left  between  the 
rounding  edges  of  the  rods  at  each  intersection.  The 
sheets  are  then  grasped  with  iron  pincers  and  held  in 
the  furnace  while  they  are  twisted  and  formed  into  a 
vase.  The  effect  of  the  bubbles  of  air  inside  the  mass 
of  glass,  increasing  and  decreasing  in  size  according 
to  the  shape  of  the  piece,  makes  the  manufacture  seem 
almost  incomprehensible. 

Cameo  Glass 

Cameo  glass  is  made  by  fusing  a  sheet  of  colored 
glass  upon  one  of  a  different  color,  so  that  they  can  be 
cut  in  cameo  effects. 

Mosaic  Glass 

Mosaic  glass  is  made  of  white  threads  on  a  blue 
ground,  laid  in  mosaic  patterns. 

Frosted  Glass 

Frosted  glass  is  made  by  rolling  the  soft  piece  in 
either  white  or  colored  powdered  glass. 


112 


GLASSWARE  DEPARTMENT 


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W 


¥■1 


Gold  is  sprinkled  over  the  surface  by  a  similar 
process. 

Laticella  Glass 

Laticella  glass  is  decorated  with  open  network  de- 
signs. These  designs  are  cut  out  of  metal  or  paper 
and  placed  on  the  glass;  they  are  held  in  place  by 
essence  of  turpentine.  A  light  powder  is  first  sifted 
over  the  pattern  and  then  it  is  removed.  When  the 
glass  is  heated  the  powder  is  melted  and  acts  as  a  resist 
to  the  acid,  into  which  the  piece  of  glass  is  then  dipped. 
The  acid  eats  away  the  uncovered  part  of  the  glass, 
leaving  a  delicate  lacelike  pattern  where  the  powder 
has  been. 

Millefiori  Glass 

Millefiori  glass  has  small  bunches  or  baskets  of 
flowers  in  natural  colors,  portraits,  or  fanciful  objects 
enclosed  in  cubes,  domes,  or  balls  of  glass.  This  type 
of  glass  is  used  in  paper  weights  or  other  small  articles. 

Coloring  of  Venetian  Glass 

This  exquisite  glassware  has  an  almost  unlimited 
range  of  colors,  and  these  are  equally  beautiful, 
whether  transparent  or  opaque.  The  best  models  are 
probably  those  that  are  made  solely  for  ornament 
rather  than  as  parts  of  table  service.     The  lovely  color- 


H 


B  C 

A — Tazza         B — Small  Covered  Vase       C — Biberon 
Figure  9.     Examples  of  Venetian  Glassware 


l;.t 


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lit 


VENETIAN  AND  BOHEMIAN  GLASS        II3 

ing  and  original  shapes  look  best  when  given  a  setting 
of  their  own  and  when  they  are  not  mingled  with  in- 
congruous pieces  of  other  types. 

American  manufacturers,  after  many  years  of  ex- 
periment, have  learned  to  make  glassware  which  has 
most  if  not  all  of  the  characteristics  of  Venetian  glass. 
One  such  manufacturer  reproduces  old  patterns,  even 
including  the  bubbles  which  are  found  in  many  old 
pieces.  The  old  colorings  such  as  turquoise,  royal 
blue,  and  amethyst,  are  also  found  in  these  beautiful 
reproductions. 

Figure  9  gives  three  examples  of  beautiful  Venetian 
glass.  Figure  A  shows  a  flat  ornamental  shallow  cup 
known  as  a  tazza.  The  shallow  bowl  is  embossed  to 
form  a  series  of  wavelets  with  angular  points  round 
the  margin.  The  supporting  stem  is  gracefully  drawn 
with  a  conical  foot  formed  of  lace  glass. 

Figure  B  shows  a  small  covered  vase  beautifully 
decorated  with  fine  white  lace-work.  The  wings  or 
handles  have  been  given  the  form  of  conventionahzed 
dragons. 

Figure  C  is  an  example  of  a  biberon  or  pitcher.  It 
is  distinguished  by  a  scalloped  mouth  and  the  medal- 
lions surmounting  the  handle  and  at  the  base  of  the 
spout.  These  medallions  are  ornamented  by  gilt  satyr 
heads  and  are  characteristic  of  the  Venetian  style. 


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GLASSWARE  DEPARTMENT 


Bohemian  Glass 

Modern  Bohemian  glass,  which  is  made  in  Bohemia, 
Saxony,  Bavaria,  and  Silesia,  is  usually  colored  or  has 
color  associated  with  it.  It  is  generally  heavier  than 
Venetian  glass,  and  in  many  cases  the  color  is 
"  flashed  "  or  put  on  in  thin  layers,  which  are  partly 
cut  away,  showing  the  clear  crystal  beneath. 

Bohemian  glass  is  found  in  table  glass,  such  as 
stemware,  bottles,  decanters,  pitchers,  flat  dishes,  and 
many  forms  of  ornamental  glass. 

The  sand  and  potash  from  which  Bohemian  glass  is 
made  are  very  fine  and  pure  and  give  it  great  bril- 
liancy and  lightness ;  because  of  the  greater  purity  of 
its  materials  it  is  clearer  than  Venetian  glass.  The 
shapes  of  Bohemian  glass  vessels  are  less  original,  but 
often  more  serviceable,  than  the  Murano  pieces  which 
they  originally  imitated. 

Methods  of  Ornamentation 

The  best  developed  form  of  decoration  is  engraving, 
which  is  done  on  the  white  crystal  or  on  flashed  glass 
with  equal  effectiveness.  A  Bohemian  named  Casper 
Lehmann  invented  the  method  of  engraving  by  holding 
the    piece   of    glass    against    the   points    of    whirling 

spindles. 

Designs  are  also  etched  with  fluoric  acid;  but  the 
etched  glass,  while  cheaper,  is  not  so  satisfactory,  be- 


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Figure  lo.     Example  of  Bohemian  Engraved  Glass 


VENETIAN  AND  BOHEMIAN  GLASS        II5 

cause  the  designs  cannot  stand  out  so  clearly  and 

sharply.  .    ,    ,    • 

Besides  the  usual  floral  and  geometrical  designs, 
Bohemian  glass  is  sometimes  decorated  with  elaborate 
pictures,  such  as  hunting  scenes  in  medallions  sur- 
rounded  by  scrollwork. 

Cutting  is  done  in  conventional  patterns,  especially 
with  flashed  glass,  which  gives  a  very  striking  effect; 
cameo  incrustation  and  enamel  painting  are  also  used. 
The  usual  colors  of  Bohemian  glass  are  deep  red, 
blue,  green,  and  amber.  Besides  the  "  pot  metal " 
colors  which  are  mixed  with  the  molten  glass  and  the 
flashed  colors  put  on  as  a  casing,  color  is  applied  with 
a  brush  and  fixed  by  firing  the  piece  as  with  china. 

History  of  Bohemian  Glass 

During  the  eighteenth  century  Bohemian  glass  be- 
came more  popular  than  the  Venetian  product  and  was 
exported  to  England,  America,  the  East,  and  even  to 
Italy.  Some  famous  pieces  are  now  to  be  found  in 
museums  and  private  collections.  It  was  highly  prized 
by  the  early  Americans,  and  after  a  period  in  which  it 
went  out  of  fashion,  it  has  again  become  popular  be- 
cause of  its  genuine  merits,  particularly  its  deep  rich 
color,  its  original  and  finely  executed  designs,  and  its 
serviceable  styles. 

Figure  lo  shows  a  rare  specimen  of  Bohemian  en- 


i     ^ 


Ii6 


GLASSWARE  DEPARTMENT 


graved  glass  of  medieval  workmanship.  It  is  a  shell- 
shaped  cup  with  deep  cuttings  which  form  a  series  of 
bold,  projecting  compartments.  The  curved  surfaces 
of  these  are  beautifully  engraved  with  figures,  scrolls, 
and  other  ornaments. 


ft 


tf. 


Chapter  XIII 
TIFFANY  FAVRILE  GLASS 

Old  Industry  Revived 

In  Tiffany  favrile  glass  we  have  a  modern  produc- 
tion which  combines  the  beautiful  rich  colors  in  old 
cathedral  windows  with  the  surface  iridescence  of  the 
ancient  Egyptian  and  the  Roman  glass  that  has  been 
buried  in  the  earth  for  so  many  centuries. 

Window  Glass 

After  a  number  of  years  of  experiment  during  which 
Mr.  Tiffany  had  the  glass  made  for  him,  he  estab- 
lished his  own  factory  in  1892  at  Corona,  Long  Island. 
Large  panes  of  flat  glass,  some  of  them  with  delicate 
opaline  colors  and  many  different  kinds  of  texture  and 
degrees  of  density  are  produced.  Some  glass  is  clear, 
some  crinkled  or  veiled,  some  clouded  or  speckled. 
The  varieties  of  color  combinations  and  textures  are 
too  numerous  to  mention. 

The  colors  for  this  rolled  glass  are  all  put  into  the 
batch  while  in  its  raw  state.  In  other  words,  it  is  not 
enameled  on  the  surface.  The  color  is  an  integral  part 
of  the  mass  itself. 

X17 


Ii8 


GL.\SSWARE  DEPARTMENT 


:h 


I    I 


There  is  other  glass,  however,  which  is  still  more 
beautiful  and  varied.  The  hot  glass  from  different 
pots  is  thrown  out  on  the  table  with  a  ladle;  as  many 
as  seven  different  colors  may  be  thrown  together. 
The  famous  draper>*  effects  are  made  by  taking  ad- 
vantage of  natural  conditions  while  rolling  and  catch- 
ing the  ends  of  the  hot  sheet  with  iron  hooks  and  crink- 
ling it  together. 

The  color  formulas  are  secret,  but  they  are  composed 
of  different  metallic  oxides  combined  to  form  different 
tints  and  hues.  Gold,  copper,  iron,  and  other  metals 
are  used  lavishly,  and  the  layers  of  glass  are  sometimes 
so  heavily  charged  with  these  oxides  that  they  are  more 
like  metal  than  glass. 

Peacock  Glass 

Early  in  the  production  of  favrile  glass  the  wonder- 
ful iridescence  of  the  peacock  feather  inspired  Mr. 
Tiffany  with  a  desire  to  reproduce  it  in  glass.  Many 
attempts  were  made  before  success  was  achieved. 
The  remarkable  color  variations  were  produced  in  each 
case  by  the  application  of  different  colored  glasses,  hav- 
ing different  chemical  constituents  in  order  that  they 
might  produce  not  only  the  diversified  iridescence,  but 
have  also  the  characteristic  body  colors. 

All  the  colors  of  peacock  glass  are  applied  during  the 
process  of  manufacture  while  the  glasses  are  in  a  plas- 


TIFFANY  FAVRILE  GLASS 


119 


tic  or  viscous  condition,  and  the  object  is  finished  be- 
fore it  is  placed  in  the  annealing  oven.-  Particular 
attention  is  drawn  to  this  fact,  for  the  reason  that  all 
imitations  of  Tiffany  peacock  vases  have  been  made  by 
the  application  of  enamel  colors  after  the  piece  is  com- 
pleted. 

Shapes 

The  blown  glass  for  table  use  and  decorative  glass 
is  fashioned  in  graceful  shapes  which  are  less  fanciful 
and  odd  than  Venetian  or  Bohemian  productions. 
They  look  more  like  Greek  or  Japanese  designs. 

Flower  motifs  are  used  for  smaller  pieces  with  the 
fine  veins  and  threads  of  color  pulled  and  twisted  by 
hooks  during  the  forming  process. 

The  iridescence  of  antique  glass  is  due  to  decom- 
position of  the  surface  brought  about  by  chemical 
action  during  the  long  period  of  exposure  to  the  air. 
The  iridescence  is  not  permanent  and  may  be  rubbed 
off.  In  favrile  glass  this  iridescence  is  reproduced  in 
the  texture  of  the  glass  by  a  secret  process  and  is  per- 
manent. 

Characteristic  Colors  of  Tiffany  Favrile  Glass 

Some  of  the  characteristic  and  unusual  color  effects 
in  Tiffany  favrile  glass  are: 

Gold  Lustre,  an  iridescent  old-gold  coloring. 


120 


GLASSWARE  DEPARTMENT 


(( 


it 


"  Samian  Red,"  the  red  of  a  lobster's  claw. 

Mazarin  Blue,"  a  deep,  rich  blue  with  a  purple 

shade. 

Tel-al-amana  "  or  Turquoise  Blue,  shading  from 

turquoise  to  peacock  green. 
"Aqua  Marine,"  the  color  of  deep  water  with 

bronze  lights  in  it,  or  pale  green  with  objects 

apparently  floating  in  water. 

In  spite  of  its  apparent  delicacy,  the  glass  is  tough 
and  durable.  "  Favrile "  is  a  coined  word  derived 
from  "  fabric,"  or  "  fabrile,"  and  means  "  made  by 
hand." 


% 


m 


Chapter  XIV 


VASES  AND  CANDLESTICKS 
Varieties 

There  are  two  kinds  of  vases,  those  which  are  in- 
tended to  hold  flowers  and  those  which  are  solely  for 
ornament.  The  flower  holders  are  usually  made  of 
glass  and  are  shaped  according  to  the  kind  and  num- 
ber of  flowers  to  be  contained. 

The  low  shapes  are : 

Low  round  bowls,  sometimes  very  shallow. 
Round  bowls  with  an  irregular  edge. 
Bowls  with  a  flaring,  ruffled  edge. 
Bowls  with  a  collar  or  ruffle  turned  over. 
Rose  bowls. 

The  medium  height  shapes  are: 

Straight-sided. 
Flaring  slightly. 
Flaring  widely. 

Funnel-shaped,    with    a    stem    supported    by    a 

standard. 
Baskets. 

121 


122 


GLASSWARE  DEPARTMENT 


Curved  gracefully  in  about  one-third  of  the  dis- 
tance from  the  top  and  then  out  again  in  a 
flowing  curve. 

Very  slender,  for  single  flowers. 

The  tall  shapes  are : 

Straight-sided  column. 

Flaring  from  a  point  near  the  base. 

Flaring  at  the  top  only. 

Very  slender,  for  single  long-stemmed  flowers. 

Same  as  in  those  of  medium  height. 

Table  Vases 

Sets  of  vases  may  consist  of  four,  five,  or  six  vases 
of  similar  shape  for  table  decoration.  The  vase  in- 
tended for  the  center  is  of  a  larger  size  than  the  others. 
They  are  often  connected  by  a  glass  chain. 

A  table  decoration  which  is  a  revival  of  an  old 
French  pattern  consists  of  a  silver  or  gilt  standard 
holding  vases  shaped  like  horns  of  plenty  and  connected 
by  ornamental  festoons  of  the  metal. 

A  very  graceful  table  vase  consists  of  a  low,  broad 
bowl  with  a  flower-like  vase  springing  from  the  center. 

These  flower  holders  may  be  found  in  cut,  pressed, 
and  art  glass  and  in  a  number  of  colors  —  white, 
green,  amber,  mulberry, .  blue,  black,  and  opalescent. 
The  clear,  delicately  tinted  or  white  glass  is  in  better 


VASES  AND  CANDLESTICKS 


123 


ill 


taste  than  highly  ornamented  glass  for  this  purpose,  as 
the  vase  should  be  only  a  setting  for  the  flowers  and 
should  not  call  attention  to  itself. 

Ornamental  Vases 

Ornamental  vases  are  of  many  graceful  shapes,  but 
are  often  quite  unsuited  for  holding  flowers.  They 
may  be  elaborately  decorated  with  gold  and  color,  and 
are  sometimes  made  of  several  different  kinds  of  glass. 
Tiffany  glass  is  often  found  in  forms  resembling 
flowers,  either  colored  to  make  the  resemblance  more 
complete  or  covered  with  delicate  tracery. 

Glass  Candlesticks 

Candlesticks  of  glass  are  usually  of  simple  forms. 
They  are : 

Four-sided 

Straight 

Smaller  at  the  top 

Curved  out  in  the  middle 

With  the  corners  cut  off 

Faceted 

Rounded 
Six-sided,  usually  straight 
Cylindrical 
Twisted 


124  GLASSWARE  DEPARTMENT 

The  bases  usually  follow  the  lines  of  the  stems,  and 
are  four-  or  six-sided,  cut  off  at  the  corners,  or  round ; 
but  sometimes  they  are  simple  in  order  to  balance  an 
elaborate  stem,  or  ornamented  to  set  off  a  plain  stem. 
Bases  of  candlesticks  should  be  large  enough  to  sup- 
port the  stick  and  the  candle  above  it.  They  are 
therefore  rather  broad  and  heavy. 

While  candlesticks  are  sometimes  found  in  colors, 
they  are  nearly  always  of  white  clear  glass  with  plain 
or  light  frosted  cutting.  The  bases  are  frequently  cut 
underneath.  The  straight-sided  Colonial  candlestick 
has  no  ornamental  cutting.  Shapes  which  are  less  se- 
vere may  have  floral  or  star  designs,  but  they  are  sim- 
ple in  style.     The  patterns  are  often  acid-engraved  or 

etched. 

Candelabra  of  glass  are  hung  with  pendants  of 
prisms  ending  in  diamond  points,  which  catch  the  light 
and  increase  their  brilliancy  by  reflection. 

Candlesticks  for  the  dining  table  are  usually  of  glass 
or  silver  as  they  then  correspond  with  the  table  fur- 
nishings. 

Miniature  candlesticks  are  used  for  the  dressmg 
table  and  for  children's  dressers  as  well  as  for  chil- 
dren's parties. 


Chapter  XV 
LAMPS  AND  LIGHTING  FIXTURES 

The  Lamp  Department 

A  Lamp  Department  includes  many  varieties  of 
lighting  standards  and  fixtures.  The  illuminant  may 
be  oil,  gas,  or  electricity,  and  the  illuminating  devices 
may  be : 

Lamps 
Candles 
Lanterns 
Wall  fixtures 
Ceiling  fixtures 

Lamps 

Oil  lamps  are  portable  because  they  are  independent 
of  a  central  lighting  plant.  A  good  oil  lamp  is  also 
less  trying  to  the  eyes  than  the  more  concentrated  elec- 
tric light,  but  on  the  other  hand  oil  lamps  are  much 
more  troublesome  as  they  need  frequent  refilling  and 
cleaning.  Oil  is  seldom  used  in  wall  or  ceiling  fixtures 
except  on  shipboard  or  in  the  country,  as  storage  bat- 

125 


126 


GLASSWARE  DEPARTMENT 


teries  now  supply  electricity  even   for  the  lights  of 
moving  trains. 

Gas,  which  may  be  supplied  by  means  of  rigid  pipes, 
is  more  widely  used  in  wall  or  ceiling  fixtures.  The 
flexible  tubes  which  are  needed  for  table  lamps  are 
made  of  rubber,  covered  with  woven  textile  tubing. 
The  tubes  are  easily  cracked  when  bent,  are  rather  stiff 
and  unwieldy,  and  not  very  durable.  They  must  be 
carefully  watched  to  prevent  leakage  of  gas  and  are 
condemned  by  fire  insurance  companies. 

The  use  of  electricity  has  added  many  new  varieties 
of  lighting  fixtures  as  well  as  duplicating  those  used 
for  candles,  oil  lamps,  and  gas.  Portable  lamps  may 
be  attached  to  a  light  flexible  cord,  which  is  often  con- 
cealed in  the  standard  and  can  be  connected  with  a 
floor  or  wall  socket  at  will. 

Types  of  Oil  Lamps 

Oil  lamps  are  made  with  either  one  or  two  flat 
wicks,  or,  in  the  case  of  student  lamps,  with  a  tubular 
wick.  The  oil  reservoir  which  feeds  the  lamp  is 
usually  below  the  wick  but  in  the  student  type  it  is  in 
a  cylindrical  well  at  the  side.  The  original  student 
lamp  was  so  constructed  that  the  oil  was  fed  evenly 
and  abundantly  to  the  tubular  wick  and  burned  with  a 
clear,  steady  flame  in  a  tall  cylindrical  chimney.  It  was 
supplied  with  a  porcelain  shade  green  on  the  upper  sid^ 


LAMPS  AND  LIGHTING  FIXTURES         12? 

and  white  underneath  which  gave  a  soft,  pleasant  read- 
ing light  that  has  not  been  surpassed,  and  seldom 
equaled,  by  any  other  device.  The  lamp  could  be  raised 
or  lowered  at  will  on  the  standard  which  consisted  of 
a  base  and  stiff  rod  to  which  the  lamp  was  attached 
by  a  screw.  These  lamps  were  of  German  manufacture 
and  are  now  almost  impossible  to  secure.  The  "student" 
lamps  now  used  have  two  flat  wicks  placed  side  by  side 
with  an  elevated  oil  well.  Double  student  lamps  have 
a  central  well  and  lamps  on  each  side. 

Oil  lamps  can  be  made  into  electric  lamps  by  merely 
putting  an  incandescent  bulb  in  place  of  the  wick  and 
attaching  a  cord  at  the  side  or  running  it  up  through 
the  base. 

Adjustable  Lamps 

Adjustable  lamps  are  so  constructed  that  they  may 
be  turned  in  various  directions,  as  well  as  raised  and 
lowered  on  the  standard.  Floor  lamps  have  wood  or 
metal  bases  and  are  conveniently  placed  behind  a  couch 
or  chair  with  the  light  exactly  where  it  is  wanted. 

Table  lamps  of  this  type  may  be  used  to  advantage 
at  a  dressing  table  or  in  a  library.  By  turning  the 
shade  upside  down  they  will  give  indirect  lighting. 
Small  adjustable  lamps  are  made  to  fasten  on  the  backs 
of  chairs  or  bedposts  for  the  benefit  of  invalids  or 
for  those  who  like  to  read  in  bed.     "Gooseneck" 


ii 


128 


GLASSWARE  DEPARTMENT 


lamps  have  a  flexible  standard  which  permits  many 
different  adjustments. 

Lamp  Chimneys 

Lamp  chimneys  protect  the  flame  of  a  lamp  in  the 
same  way  as  the  sides  of  the  lantern  or  the  bell  around 
a  candle.  The  usual  shape  for  a  lamp  chimney  is  a 
shape  between  that  of  a  cylinder  and  a  cone  cut  off 
at  the  top.  It  is  larger  at  the  base  than  near  the  top, 
but  not  so  large  in  proportion  as  the  base  of  a  cone. 
The  Argand  or  student  lamp  chimney  is  a  straight 
cylinder  with  a  collar  or  projection  near  the  bottom. 

Lamp  chimneys  must  be  well  annealed  or  they  will 
break  when  heated.  They  should  never  be  damp  when 
the  lamp  is  lighted  since  a  drop  of  water  will  cool  the 
spot  it  touches  and  result  in  breakage. 

Lamp  Stands 

Lamp  stands  or  bases  may  be  of  wood,  metal, 
pottery,  or  glass.  Beautiful  ones  are  made  from  bronze 
and  porcelain  vases  by  piercing  the  side  or  bottom  of 
the  vase  to  admit  the  cord,  and  adding  a  lamp  socket 
and  shade  frame  to  the  top. 

Floor  lamps  have  standards  of  plain  mahogany  or 
of  gilded  and  painted  wood  in  French  and  oriental 
designs  which  are  sometimes  very  elaborate.  They  are 
also  of  iron,  bronze,  and  brass  or  of  metal  painted  in 


LAMPS  AND  LIGHTING  FIXTURES 


129 


enamels.  Adjustable  floor  lamps  have  very  plain 
standards. 

The  less  expensive  standards  for  either  floor  or  table 
lamps  are  made  of  a  composition  metal  which  is  poured 
into  bronze  molds  and  sprayed  by  means  of  the  air 
brush  or  spraying  machine  with  enamel  and  lacquer 
finishes. 

Old  ivory  is  produced  by  spraying  with  white  or 
cream-colored  enamel  and  spreading  a  brown  solution 
over  it.  In  some  places  the  solution  is  entirely  removed 
and  in  others  only  partially  wiped  off. 

A  green  antique  bronze  effect  is  produced  by  wiping 
a  greenish  solution  on  a  copper  bronze  base. 

Very  hard  water -proof  enamels  may  be  mistaken 
for  the  metals  which  they  imitate  if  they  are  put  on 
skilfully.  They  are  sometimes  almost  as  viscous  as 
glass  and  can  only  be  applied  by  the  spraying  process. 


Lampshades 

Lampshades  may  be  of  metal,  porcelain,  glass,  paper, 
or  textiles  in  many  forms. 

Metal  shades  for  reading  lamps  may  be  solid  with 
brass  or  copper  above  and  a  silvered  surface  beneath 
to  reflect  the  light.  The  light  is  too  concentrated  to 
be  pleasant  in  a  room  without  other  illumination.  Metal 
shades  are  also  made  in  pierced  designs  sometimes 
studded  with  glass  jewels  in  oriental  fashion. 


m 


I30 


GLASSWARE  DEPARTMENT 


Porcelain  lampshades  give  a  soft,  pleasant  light  and 
are  made  in  almost  unlimited  varieties,  though  the  green 
and  white  are  most  common. 

Glass  shades  are  now  usually  made  either  in  the 
heavy  semi-translucent  opal  glass  or  in  iridescent 
Tiffany  glass.  The  light  metal  frames  in  which  opal 
glass  is  set  are  usually  of  composition  molded  in  the 
desired  shape  and  sprayed  with  enamel.  Curved  pieces 
are  heated  and  bent  from  flat  sheets  of  glass  by  the 
shade  manufacturer.  Glass  domes  are  of  molded  or 
pressed  glass.  Many  of  these  are  painted  on  the  under- 
side and  fired  in  a  kiln. 

Parchment  shades  are  made  of  a  specially  prepared 
paper  which  is  given  a  hard  leathery  finish. 

A  textile  shade  having  the  appearance  of  painted 
glass  is  made  of  scrim  or  cheese-cloth,  hung  loosely 
on  a  metal  frame  and  varnished  until  it  shrinks  to  fit 
the  foundation.  It  is  painted  with  enamels  and  when 
finished  has  the  translucence  and  brilliant  surface  of 
painted  glass. 

Shirred  silk,  tapestry,  and  cretonne  are  all  used  in 
making  lampshades.  An  interesting  lamp  for  a  library 
consists  of  a  bronze  standard  supporting  a  bowl  lined 
with  mirrors  which  reflect  the  light  of  a  high  wattage 
lamp  upon  the  ceiling.  Beneath  the  bowl  are  three 
other  bulbs  to  make  a  reading  light,  and  suspended 
from  the  top  of  the  bowl  is  a  white  lined  silk  shade 


LAMPS  AND  LIGHTING  FIXTURES 


131 


which  makes  the  combination  look  like  a  well-propor- 
tioned lamp  of  ordinary  construction. 

Candlesticks  and  Candelabra 

Candlesticks  are  also  found  in  the  Lamp  Depart- 
ment. Besides  the  glass  candlesticks  described  in  Chap- 
ter XIV,  those  of  porcelain  or  bisque,  brass,  bronze, 
iron,  and  wood  are  found.  Porcelain  candlesticks  are 
usually  simple  in  shape,  being  round,  square,  or  col- 
umnar with  plain  bases.  They  are  decorated  with  gold 
bands,  fluting,  and  little  painted  flowers.  Some  French 
candlesticks  have  Watteau  figures  at  the  side. 

Brass  and  bronze  candlesticks  are  simple  in  design 
unless  they  are  of  oriental  patterns  when  they  are  apt 
to  have  dragons  coiled  around  them.  Some  beautiful 
Egyptian  candlesticks  are  of  pierced  brass.  Russian 
brass  candlesticks  and  candelabra  have  a  kind  of  fret- 
work ornament. 

Iron  candlesticks  are  sometimes  very  elaborate  as 
wrought  iron  is  soft  and  malleable  and  may  be  fash- 
ioned into  scrollwork  or  plant  forms  which  are  often 
graceful  and  ornamental. 

Candelabra  are  stands  or  holders  for  two  or  more 
candles.  They  are  made  of  the  same  materials  as 
single  candlesticks,  but  brass  is  the  most  common 
material.  Russian  candelabra  with  five  or  seven 
branches  have  a  somewhat  oriental  appearance  due  to 


W' 


132 


GLASSWARE  DEPARTMENT 


their  fretwork  ornamentation.     Hanging  candelabra 
are  also  made  of  hammered  brass. 

Candle  protectors  are  shaped  like  an  inverted  bell 
with  the  opening  at  the  top.  They  are  found  with 
brass  candlesticks  which  have  a  deep  broad  saucer  and 
ring  for  carrying,  as  in  an  antique  bedroom  candle. 
The  deep  bell  covers  the  entire  candle  and  protects  it 
from  gusts  of  wind.  The  modern  candlestick,  bell  and 
all,  is  a  reproduction  of  the  plain  Colonial  design. 

Glass  balls  and  prisms  decorate  many  candlesticks 
and  chandeliers  (originally  meaning  "candle-holder"). 
Gilt  candlesticks  and  candelabra  with  marble  bases  and 
a  row  of  glass  prisms  hanging  beneath  the  candle  are 
very  bright  and  sparkling.  When  the  prisms  are  raised 
at  the  side  to  the  level  of  the  flame,  the  brilliancy  is 
greatly  increased.    The  designs  for  these  are  French. 

Chandeliers  decorated  with  many  rows  of  balls  or 
prisms  are  made  for  use  with  either  candles,  gas,  or 
electricity.  The  light  reflected  from  so  many  sparkling 
facets  makes  the  whole  fixture  shine  like  gorgeous 
chains  of  precious  stones.  When  chandeliers  of  this 
type  are  used  in  dining-rooms  and  banquet  halls,  the 
latter  are  given  an  atmospheric  chill  because  of  the 
coldness  of  the  light.  The  glass  prisms  and  tears  have 
the  appearance  of  suspended  icicles.  Light  of  a  red, 
glowing  tone,  exemplified  by  indirect  candle  light,  adds 
to  the  cheerfulness  and  warmth. 


LAMPS  AND  LIGHTING  FIXTURES 


133 


Lanterns 

Lanterns  may  be  either  movable  or  fixed.  They 
may  take  the  form  of  either  candles,  lamps,  gas  burners, 
or  incandescent  lights  protected  on  all  sides  by  a  box, 
or  cover  of  glass  and  metal  combined.  Oriental  lanterns 
have  jewels  of  glass  inserted  in  a  metal  fretwork  more 
or  less  open. 

Lanterns  are  suspended  above  or  beside  doorways 
and  in  exposed  arches  or  passages.  In  the  country  a 
lantern  is  the  light  for  those  who  travel  on  foot  or  by 
wagon  or  carriage.  For  automobiles,  lanterns  are  re- 
placed by  the  oil  or  electric  lamp  with  a  lens  (see 
Chapter  XVI)  to  redirect  the  light  from  the  polished 
reflector  and  lamp. 

Ships'  lanterns  have  cylinder  lenses  to  make  the 
light  source  appear  as  a  "pencil"  of  light,  by  which 
beam  candlepowers  are  built  up.  Such  lanterns  are 
used  exclusively  for  signals. 

Lighting  Fixtures 

Wall  and  ceiling  fixtures  are  of  many  kinds,  includ- 
ing the  older  types  of  candelabra  and  lanterns  and  also 
many  new  ones  made  possible  by  the  use  of  electricity, 
which  is  fast  taking  the  place  of  all  other  methods  of 
lighting. 

Side  fixtures  for  gas  have : 


f  f 


ri 


134 


GLASSWARE  DEPARTMENT 


1.  An  open  flame  usually  surrounded  by  a  glass 

shade  or  globe  open  at  the  top. 

2.  An  incandescent  mantle  covering  the  outlet  in 

order  to  increase  the  light  per  cubic  foot  of 
gas  burned.    These  should  be  protected  from 
drafts  by  a  small  glass  shell  in  addition  to 
the  outer  globe  or  shade. 
Side  fixtures  for  electricity  are : 

1.  Candelabra   with   porcelain   candles   and   either 

pointed  or  round  incandescent  lamps  to  rep- 
resent the  flame. 

2.  Bells  or  other  pendent  lights. 

3.  Lights  inserted  in  the  wall  and  covered  with 

translucent  glass. 

4.  Segments  of  bowls,  molding,  or  other  fixtures 

which  conceal  the  light  from  below  and  reflect 
it  upon  the  upper  wall  and  ceiling. 
Ceiling  fixtures  for  gas  are  all  hanging  and  only 
differ  in  the  shape  of  the  fixture,  the  number  of  lights, 
and  other  details. 

Ceiling  fixtures  for  electricity  may  be : 

1.  Pendent  with  visible  lights  in  bells,  candles,  lan- 

terns, or  other  forms. 

2.  Pendent  with  invisible  lights: 

(a)  In  translucent  bowls — semi-indirect  sys- 

tem. 

(b)  In  metal  bowls — indirect  system. 


LAMPS  AND  LIGHTING  FIXTURES         135 

3.  Combinations  of  the  indirect  and  semi-indirect. 

4.  Ceiling  lights  either  visible  or  concealed  with 

translucent  glass. 
Electric  light  fixtures  should  always  be  characterized 
by  grace  and  beauty,  although  many  of  them  are  not. 
The  adaptability  of  electricity  has  made  it  possible  to 
reproduce  old  types  of  lighting  and  to  create  new  ones, 
and  the  many  new  methods  of  treating  and  decorating 
glass  give  a  very  wide  range  for  originality.  Yet  we 
see  hosts  of  ugly  designs  as  well  as  beautiful  ones. 

Indirect  Lighting 

Indirect  lighting  is  secured  by  throwing  all  the  light 
rays  upon  a  reflecting  surface  by  which  they  are  diffused 
over  a  large  space. 

The  concentrated  light  of  high  wattage  lamps  may 
be  used  to  great  advantage  in  this  way.  The  ceiling 
so  lighted  gives  a  soft  glow  which  is  very  pleasant 
to  the  eyes. 

The  lights  are  concealed  in  metal  bowls  lined  with 
mirrors  which  reflect  the  light  either  upon  the  ceiling 
or  upon  white  porcelain  discs  which  again  reflect  it 
but  break  up  and  refract,  or  turn,  the  rays  so  that  they 
are  scattered  and  softened. 

Semi-Indirect  Lighting 
The  great  objection  to  indirect  systems  is  that  the 


13^ 


GLASSWARE  DEPARTMENT 


II 


light  source  appears  as  a  black  spot  on  a  light  ceiling. 
This  is  psychologically  wrong.  Furthermore  the  main- 
tenance costs  are  unfavorable. 

Semi-indirect  or  shadowless  lights  aim  to  secure 
the  same  softness  and  diffusion  with  greater  light 
efficiency. 

Semi-indirect  lights  have  white  or  ground  glass 
globes  or  bowls  instead  of  the  metal  ones.  These 
"filter"  the  light  rays  while  the  ceiling  or  disc  above 
reflects  and  disperses  them. 

Daylight  Glass 

Colored  articles  viewed  by  daylight  may  have  an 
entirely  different  appearance  when  viewed  by  artificial 
light  of  a  reddish  character.  Cloth  or  ribbon  carefully 
matched  for  color  by  artificial  light  may  not  match  at 
all  when  viewed  by  daylight.  Thus  there  is  a  demand 
for  artificial  daylight  for  color  matching.  Very  few 
realize  what  is  demanded  to  produce  artificially  a  light 
similar  to  that  emitted  from  the  sky. 

It  has  been  known  for  a  long  time  that  in  daylight 
there  are  certain  proportions  of  all  the  different  colors 
in  the  visible  spectrum.  Upon  analysis  of  the  light 
emitted  from  our  most  modern  lamp  it  has  been  found 
that  the  greatest  per  cent  lies  in  the  red  end  of  the 
spectrum,  while  very  little  of  the  blue  is  present.  If 
we  surround  such  a  light  with  a  glass  which  functions 


LAMPS  AND  LIGHTING  FIXTURES 


137 


as  a  selecting  medium,  transmitting  red,  green,  and  blue 
light  in  the  same  proportions  that  appear  in  daylight 
and  absorbing  the  rest,  we  will  have  a  so-called  "day- 
light glass."  This  glass  when  viewed  in  daylight  has 
a  bluish  appearance  because  it  transmits  all  the  blue, 
absorbing  some  of  the  green  and  a  large  percentage  of 
the  red. 

To  produce  a  true  artificial  daylight  in  this  way, 
efficiency  must  be  sacrificed,  since  the  light  from  the 
red  end  of  the  spectrum,  forming  about  80  per  cent 
of  the  whole,  is  in  part  absorbed  by  the  daylight  glass 
and  is  therefore  a  total  loss.  Consequently  this  ideal 
reproduction  of  daylight  is  never  sought.  In  daylight 
lamps,  Mazda  ''C2;'  75  per  cent  of  the  light  from  the 
filament  is  transmitted  by  the  glass.  In  daylight  illumi- 
nating glassware  about  40  per  cent  of  the  light  from 
the  filament  is  absorbed,  while  in  local  color-matching 
units,  the  glass  reproduces  daylight  more  nearly,  and 
therefore  is  still  more  inefficient  than  the  two  preced- 
ing. When  color-matching  glass  is  used,  12  watts  per 
candle  produce  the  same  illumination  as  i  watt  per 
candle  without  the  glass. 

History  of  Lamps 

The  use  of  lamps  is  very  ancient,  though  the  ancient 
lamp  would  be  a  poor  substitute  for  the  modern  one. 

The  t)^e  found  in  Grecian  ruins  and  seen  in  old 


M/ 


i 


138 


GLASSWARE  DEPARTMENT 


drawings  was  a  sort  of  shallow  pitcher  with  a  spout 
or  nozzle  at  one  end  for  the  wick  and  a  ring  or  flattened 
projection  at  the  other  for  a  handle.  In  the  middle 
was  a  hole  through  which  the  oil  was  poured.  Some- 
times there  were  several  holes  for  wicks.  These  lamps 
were  made  of  terra  cotta  or  of  bronze.  They  were 
often  decorated  and  also  made  in  fantastic  shapes.  Only 
vegetable  or  animal  oils  were  used,  none  of  which  were 
so  satisfactory  as  the  modern  petroleum.  Wicks  were 
of  twisted  or  plaited  strands  of  flax  or  cotton. 

Lamps  were  also  suspended  by  chains.  They  were 
similar  to  the  hand-lamps  in  shape  and  material,  but 
the  decoration  was  on  the  under  side.  Lamps  burning 
incense  were  used  in  temples  and  at  shrines. 

The  words  "candle"  and  *1amp"  are  used  inter- 
changeably in  the  Bible.  There  were  no  candles  of  the 
modern  type  and  candlesticks  were  really  lamp  stands. 
The  seven-branched  golden  candlestick  of  the  Jewish 
tabernacle  had  seven  lamps  at  the  ends  of  its  branches. 

The  simplest  form  of  portable  light  was  the  torch 
which  consisted  of  a  long  pole,  the  end  of  which  had 
been  dipped  in  pitch  or  covered  with  some  other  in- 
flammable and  slow-burning  material. 

Lanterns  are  also  of  very  ancient  origin.  The  earlier 
ones  were  covered  with  horn,  bladder,  or  oiled  paper, 
which  was  more  or  less  translucent.  Chinese  and 
Japanese  paper  lanterns  have  been  very  popular  in 


LAMPS  AND  LIGHTING  FIXTURES 


139 


Europe  and  America  because  of  their  gay  colors  and 
sometimes  fantastic  shapes.  The  Japanese  Feast  of 
Lanterns  is  one  of  the  most  brilliant  and  beautiful  of 
national  festivals. 

The  discovery  in  1853  of  a  method  by  which  petro- 
leum or  coal  oil  could  be  refined  and  used  for  lighting 
made  almost  as  great  a  change  as  the  invention  of  the 
incandescent  light.  Before  that  time,  animal  and  vege- 
table oils,  especially  sperm  oil  from  the  sperm  whale, 
were  used  for  lamps  and  lanterns. 

Illuminating  gas  began  to  be  used  in  1802  and  the 
incandescent  gas  light  in  1826.  The  incandescent  elec- 
tric lamp  was  invented  by  Edison  in  1879.  It  consists 
of  a  bulb  containing  a  thin  platinum  wire  which  be- 
comes incandescent  when  an  electric  current  passes 
through  it. 


Chapter  XVI 
OPTICAL  GLASS 

Requirements  of  Optical  Glass 

The  behavior  of  glass  toward  light  rays  is  not  only 
the  source  of  its  beauty  but  makes  it  one  of  the  most 
useful  of  all  materials.  The  optical  properties  of  glass 
magnify  the  range  and  power  of  human  sight  when  used 
in  the  telescope  or  microscope,  and  correct  defects  in 
vision  when  used  in  eyeglasses  or  spectacles.  We  can 
hardly  imagine  the  modern  world  without  glass  lenses. 

The  requirements  of  optical  glass  are  so  much  more 
rigid  than  those  of  ordinary  types  that  it  must  be  made 
of  exceedingly  refined  materials  fused  in  special  fur- 
naces, with  scientific  exactness  at  every  stage  of  the 

process. 

The  value  of  optical  glass,  especially  for  large  lenses, 
depends  upon  its  transparency,  freedom  from  color,  and 
homogeneity.  Glass  which  we  are  accustomed  to  call 
"transparent"  really  absorbs  a  considerable  amount  of 
light,  as  we  may  see  by  looking  through  several  sheets 
of  window  glass  placed  together.  When  this  glass  has 
a  decided  color,  such  as  a  greenish  tint,  it  absorbs  still 

140 


OPTICAL  GLASS 


141 


more  light.  Now  for  tableware  or  window  glass  this 
tint  may  be  overcome  by  using  decolorizing  materials, 
such  as  arsenic,  cobalt,  or  manganese  (see  pages  9  and 
16),  but  these  do  not  really  take  out  the  color;  they 
only  neutralize  it  and  they  limit  still  further  the  trans- 
parency of  the  glass.  Therefore  they  cannot  be  used 
when  transparency  is  so  important.  The  original 
materials  must  be  as  pure  as  it  is  possible  to  make  them. 

Veins  or  Striae 

Homogeneity,  or  "sameness,"  is  of  the  greatest  im- 
portance in  optical  glass.  In  order  to  understand  this 
we  must  remember  that  glass  is  not  a  simple  substance, 
or  even  a  solid  compound  substance,  but  a  mixture  of 
several  materials  which  have  hardened  while  in  a  viscous 
state.  During  the  processes  of  melting  and  fining,  these 
materials  are  not  distributed  in  exactly  the  same  pro- 
portions all  through  the  glass,  and  the  result  is  that 
even  the  clearest  "plate,"  if  looked  at  from  the  end 
(through  its  greatest  thickness),  will  be  seen  to  have 
veins  or  striae  running  through  it  where  the  mixing 
has  been  imperfect.  Any  alumina  or  other  impurity 
which  the  hot  metal  has  absorbed  from  the  crucible, 
even  though  so  small  an  amount  that  it  could  only  be 
discovered  by  a  chemical  analysis,  will  also  cause  these 
streaks  or  veins. 

They  are  practically  invisible  in  glass  of  ordinary 


142 


GLASSWARE  DEPARTMENT 


thickness  but  they  are  a  serious  defect  in  optical  glass, 
because  they  deflect  the  rays  of  light.  The  most  per- 
sistent experiments  and  laborious  processes  have  been 
used  to  eliminate  these  veins. 

Furnaces  and  Crucibles 

The  manufacture  of  optical  glass  is  an  exceedingly 
expensive  operation.  First  the  furnaces  must  be  small, 
containing  only  one  or  two  pots,  since  they  need  constant 
attention.  The  crucibles  are  made  of  specially  prepared 
refractory  clay  and  heated  for  several  days  in  a  kiln 

near  the  furnace. 

When  the  pot  has  reached  the  proper  temperature  it 
is  taken  up  on  an  iron  fork  and  quickly  transferred  to 
the  furnace.  The  opening  is  then  bricked  up,  leaving 
only  the  hole  through  which  the  materials  are  to  be 
introduced  and  the  pot  is  heated  still  further.  Finally, 
just  before  the  glass  materials  are  poured  in,  a  small 
quantity  of  cullet  of  the  same  composition  as  the  glass 
which  is  to  be  made,  is  thrown  in  and  allowed  to  melt. 
This  makes  a  glass  coating  over  the  fire  clay  and  pre- 
vents impurities  from  becoming  absorbed  by  the  new 
glass  batch. 

Materials 

Materials  for  optical  glass  must  be  pure  and  finely 
pulverized  in  order  that  the  melting  and  mixing  shall  be 


II 


OPTICAL  GLASS 


143 


I  t: 


perfectly   even.      For    special    purposes    many    new 
materials  are  used  such  as : 

Hydrated  oxide  of  alumina  (instead  of  silica) 

Barium  nitrate 

Zinc  oxide 

Boric  acid 

Flourine 
The  proportions  of  the  materials  are  also  varied  to 
such  a  degree  that  there  is  a  long  list  of  glasses  to  suit 
every  optical  need.  There  is,  however,  great  danger 
in  altering  the  chemical  composition  of  glass  because 
it  can  easily  lose  its  power  of  resistance  to  attacks  by 
acids  or  alkalies.  Some  of  the  finest  optical  glass  will 
become  blurred  in  a  very  short  time  if  exposed  to 
dampness  or  even  to  the  atmosphere. 

Manufacture 

The  materials  are  put  in  the  pot  very  slowly  as  they 
boil  up  at  first  and  the  air  bubbles  must  all  be  expelled. 
When  the  pot  is  full  it  is  closed  except  for  a  hole 
through  which  the  "stirrer,"  usually  of  fire  clay,  is  in- 
troduced. This  stirrer  is  kept  in  constant  motion  in 
order  to  make  the  mixture  uniform  until  the  process 
of  fining  is  complete.  It  is  then  sometimes  withdrawn, 
but  is  often  allowed  to  remain  bedded  in  the  hardening 
glass. 

The  glass  is  cooled  as  rapidly  as  possible  without 


144 


GLASSWARE  DEPARTMENT 


'  I 


chilling  any  one  part  more  than  another ;  after  the  cool- 
ing has  reached  a  certain  point  the  pot  is  placed  in  an 
annealing  kiln  and  the  process  continues  more  slowly. 
Otherwise  the  glass  would  fly  to  pieces. 

When  cold  the  fire  clay  is  broken  off,  sometimes 
leaving  a  solid  mass  but  more  often  the  glass  has  been 
cracked  and  falls  into  a  number  of  pieces.  These  are 
not  equally  clear  and  some  are  rejected  at  once.  The 
best  pieces  are  pressed  into  iron  molds  and  heated  until 
they  take  the  form  of  plates,  discs,  or  blocks.  When 
cooled  polarized  light  is  passed  through  this  greatest 
diameter  (where  two  faces  have  been  ground  flat  and 
parallel)  in  order  to  detect  striae.  The  entire  batch  may 
yield  not  more  than  20  or  25  per  cent  of  perfect  glass 
and  large  pieces  are  much  rarer  than  small  ones.  The 
cost  of  lar^e  lenses  is  therefore  much  greater  in  pro- 
portion to  their  weight. 

Jena  Glass 

Modern  optical  glass  was  revolutionized  by  the  ex- 
periments of  E.  Abbe  and  O.  Schott,  two  German 
scientists  who  established  a  laboratory  and  works  at 
Jena.  In  1885  they  received  a  grant  from  the  govern- 
ment, and  with  this  aid  were  able  to  perfect  their 
processes  until  Jena  glass  became  the  recognized 
standard  for  the  world. 

One  of  the  serious  handicaps  to  the  Allies  in  the 


OPTICAL  GLASS 


145 


Great  War  was  their  inability  to  obtain  Jena  glass  for 
range-finders,  periscopes,  field  glasses,  and  other  optical 
instruments.  Before  the  war  closed  England,  France, 
and  America  were  making  optical  glass  declared  to  be 
as  good  as  that  of  Jena. 

American  Optical  Glass 

In  America  the  demand  for  the  rapid  production  of 
field  glasses  and  other  instruments  for  the  army  and 
navy  has  led  to  a  method  of  cooling  which  is  less  waste- 
ful and  expensive  but  produces  a  less  perfect  glass. 

The  process  of  melting  and  fining  is  the  same  but 
the  contents  of  the  crucible  is  carefully  poured  out  on 
a  slab,  as  in  rolled  plate,  instead  of  cooling  in  the  pot. 
The  bottom  and  sides  of  the  pot  are  chilled  in  order  to 
keep  the  temperature  even  and  the  sheet  of  glass  formed 
in  this  way  is  less  likely  to  splinter  and  crack  than  the 
thicker  mass.  No  part  of  this  glass  is  entirely  free  from 
striae  but  they  are  so  slight  that  the  glass  will  serve 
equally  well  for  many  purposes.  Photograph  lenses, 
spectacles,  and  field  glasses  are  made  from  this  glass. 

The  annealing  of  optical  glass  is  a  very  slow  process. 
It  is  done  in  kilns  and  takes  from  five  or  six  days  to  a 
number  of  weeks. 

Lens-Grinding 

The  grinding  of  all  lenses  is  a  tedious  process,  but 


' 


146 


GLASSWARE  DEPARTMENT 


large  telescope  lenses  are  so  extremely  difficult  to  make 
that  only  a  few  men  in  the  world  have  been  entrusted 
with  them.  The  greatest  lens-making  astronomer  in 
the  world  was  the  late  Dr.  John  A.  Brashear  who 
ground  the  lenses  for  the  Yerkes  and  Mt.  Wilson 
observatories.  The  Yerkes  telescope  at  Williams  Bay, 
Wisconsin,  is  the  largest  of  its  kind,  the  lens  being  40 
inches  in  diameter.  At  Mt.  Wilson  there  is  a  lens  72 
inches  in  diameter,  and  in  Canada  one  100  inches  in 
diameter,  weighing  2]/^  tons,  but  th'^se  are  both  mirror 
lenses  in  which  minute  defects  would  not  be  fatal.  (See 
Chapter  IX.) 

For  panoramic  sight,  the  surface  of  a  lens  must  be 
correct  to  1/100,000  of  an  inch.  French  periscope 
lenses  were  practically  perfect,  as  they  must  be  to 
photograph  the  flight  of  a  cannon  ball.  All  photo- 
graphic lenses  must  be  exceedingly  accurate. 

Lenses  and  Prisms 

Lenses  and  prisms  are  shaped  so  that  they  will 
change  the  course  of  the  rays  of  light  which  pass 
through  them.  Lenses  have  curved  surfaces  which  bend 
the  light  rays,  and  prisms  have  plane  or  flat  surfaces 
which  are  placed  so  that  they  turn  the  light  rays  and  at 
their  edges  break  up  the  white  light  into  the  colors 
which  compose  it. 

Lenses  may: 


OPTICAL  GLASS 


147 


1.  Magnify  or  produce  an  image  larger  than  the 

object,  as  in  a  microscope. 

2.  Reduce  the  size  of  the  image,  as  in  a  photo- 

graphic camera. 

3.  Bend  all  the  rays  into  a  "pencil"  of  light,  as  in 

a  lighthouse. 

4.  Collect  heat  and  light  rays,  as  in  a  burning  glass. 

Without  lenses  and  prisms  we  should  have  no  tele- 
scopes or  magnifying  glasses,  no  spectroscopes,  or  even 
eyeglasses  to  correct  defects  in  human  sight. 

Spectacles  or  eyeglasses  may  be  either  flat,  colored 
glass  merely  to  protect  the  eyes  from  light  or  to  con- 
ceal deformities,  or  they  may  be  an  aid  to  defective 
sight. 

For  correcting  defective  vision,  prisms  and  spheri- 
cal and  cylindrical  lenses  are  used.  Prisms  correct 
double  vision.     Spherical  lenses  are: 

1.  Convex,    to    correct    "long    sight"    (hyperme- 

tropia). 

2.  Concave,  to  correct  "short  sight"  (myopia). 

Compound  and  cylindrical  lenses  are  useful  in  correct- 
ing various  forms  of  defective  eyesight. 

These  lenses  are  commonly  made  of  crown  glass  (see 
P^ge  155)  or  rock  crystal  pebbles. 

Opera  glasses  and  field  glasses  are  small  telescopes 
with  two  or  more  lenses  so  adjusted  that  they  magnify 


Jl 


148 


GLASSWARE  DEPARTMENT 


objects  at  a  distance  and  seem  to  bring  them  near  to  the 
eye*  Crown  glass  or  rolled  optical  glass  is  used  for 
these  lenses  as  the  striae  are  invisible  unless  the  lens 
is  viewed  edgewise. 

For  compound  lenses  or  other  union  glass  it  is  neces- 
sary to  have  glasses  of  exactly  the  same  coefficient  of 
expansion.  To  test  this  the  glass  is  blown  in  con- 
centric balls  with  one  glass  interior  and  the  other 
exterior.  If  the  outer  one  expands  less  than  the  inner 
it  will  crack  and  split  off.  The  glasses  are  then  reversed 
and  the  experiment  repeated. 

Laboratory  Glass 

In  chemical  or  physical  laboratories,  glass  is  an  in- 
dispensable material.  Jars,  tubes,  retorts,  and  crucibles 
are  made  of  it  because  of  its  transparency,  cleanliness, 
and  relatively  great  resistance  to  the  action  of  chemicals. 

It  is  corroded  by  strong  alkalies,  but  the  only  acid 
which  has  a  noticeable  effect  upon  it  is  hydrofluoric. 
It  is  also  a  non-conductor  of  electricity  which  makes  it 
an  essential  part  of  electrical  equipment. 

For  laboratory  use,  however,  even  the  slight  effects  of 
chemicals  on  ordinary  glass  are  serious  drawbacks  in 
making  experiments  and  the  danger  of  breakage  either 
from  shock  or  from  sudden  changes  in  temperature 
has  caused  scientists  to  try  new  combinations  of 
materials  in  order  to  overcome  these  defects. 


OPTICAL  GLASS 


149 


Laboratory,  as  well  as  optical  glass,  was  developed 
with  the  greatest  success  in  Germany  at  the  Jefia  factory 
which  became  the  center  of  the  world's  supply.  When 
the  supply  was  cut  off  by  the  Great  War  other  countries 
began  to  make  experiments  of  their  own. 

In  the  United  States  five  or  six  new  factories  were 
soon  started  in  order  to  fill  this  great  need  and  much 
of  their  product  has  been  passed  by  the  Bureau  of 
Standards  by  which  all  glass  made  for  laboratory  use 
must  be  tested.  Seven  tests  are  given  in  the  following 
order  to  determine  the  resistance  of  the  glass : 

1.  Water 

2.  Mineral  acids 

3.  Carbonate  alkalies 

4.  Caustic  ** 

5.  Ammonia  and  salts  of  ammonia 

6.  Heat  shock 

7.  Mechanical  shock 

Resistance  to  chemicals  and  heat  is  even  more  im- 
portant than  to  mechanical  shock,  such  as  dropping  or 
striking,  which  may  be  more  easily  guarded  against. 

Some  of  the  materials  used  in  these  new  glasses  are 
rare  and  expensive  and  the  process  of  manufacture 
requires  much  more  care  than  ordinary  glass.  Their 
future  development  in  this  country  may  depend  on  some 
sort  of  government  support,  such  as  the  Jena  manu- 
facturers have  had. 


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GLASSWARE  DEPARTMENT 


Thermometers 

Thermometer  tubes  are  made  of  blown  glass  drawn 
out  very  fine.  One  of  the  characteristics  of  viscous 
glass  is  that  it  will  retain  the  shape  given  to  a  tube  by 
the  blowing  process  no  matter  how  finely  it  may  be 
drawn.  If  the  opening  is  triangular  in  the  beginning 
it  will  remain  triangular  and  not  become  round. 

Clinical  thermometers,  for  use  in  testing  fever  tem- 
peratures, have  a  triangular  tube,  so  small  that  the 
mercury  cannot  be  seen  except  when  the  instrument  is 
held  in  certain  positions  and  will  remain  suspended  until 
shaken  down. 

The  white  line  seen  in  the  tubes  of  some  ther- 
mometers is  made  by  flattening  a  cake  of  white  enamel 
on  the  side  of  the  bubble  of  glass  and  dipping  them 
together  into  the  molten  glass  again.  When  "drawn" 
the  enamel  follows  the  line  of  the  tube.  (See  Chapter 
XII.) 


Chapter  XVH 

WINDOWS  AND  WINDOW  GLASS 

Kinds  of  Glass  Used  in  Windows 
The  glass  used  in  windows  may  be : 

Sheet  glass 
Plate  glass 
Rolled  plate 
Figured  rolled  plate 
Polished  rolled  plate 

Sheet  Glass  is  blown  in  cylinders  5  feet  or  more  in 
length.  These  cylinders  are  split  open  and  flattened 
out  in  a  kiln.  The  glass  is  graded  according  to  its 
freedom  from  wavy  lines,  air  bubbles,  and  other 
defects. 

Plate  Glass  is  made  by  grinding  and  polishing  the 
best  quality  of  sheet  glass  on  both  sides  in  order  to 
remove  the  wavy  surface. 

Rolled  plate  is  made  by  pouring  the  glass  out  upon 
a  flat  surface  and  rolling  it.  Rough  cast  plate  is  not 
transparent,  but  the  surface  may  be  polished  like  sheet 
glass. 

151 


1) 


152  GLASSWARE  DEPARTMENT 

Figured  rolled  plate  is  made  by  means  of  rollers  with 
engraved  surfaces  which  press  a  pattern  into  the  glass 
before  the  metal  has  hardened.  Rough  and  figured 
rolled  plate  is  used  for  glass  screens  and  for  skylights 
where  transparency  is  not  desired. 

Polished  rolled  plate  is  much  heavier  than  sheet  glass, 
ranging  in  thickness  from  3/16  of  an  inch  upward.  It 
is  used  for  large  panes,  such  as  those  in  shop  windows. 

Window  Glazing 

Window  glazing,  the  art  of  setting  glass,  has  evolved 
the  following  forms  of  windows : 

Double-hung 

Casement 

French 

English  casement 

Leaded  lights 

Double-Hung  Windows 

The  windows  to  which  we  are  accustomed  in  modern 
houses  are  made  in  two  sashes,  with  or  without  a  central 
bar  dividing  the  panes  of  glass.  These  sashes  are  hung 
in  the  window  frame  on  pulleys  with  weights  at  the  end 
of  each  cord  to  balance  the  sash,  which  may  be  raised 
and  lowered  with  ease.  In  country  houses  may  be 
found  windows  which  have  no  weights  and  therefore 


WINDOWS  AND  WINDOW  GLASS 


153 


require  spring  bolts  which  slip  into  holes  in  the  frame 
and  hold  them  at  certain  heights. 

In  double-hung  windows  the  glass  is  set  by  the 
glazier  in  a  groove  near  the  outside  of  the  framework 
of  the  sash  and  made  secure  with  putty  or  cement 
pressed  down  around  the  edges  on  the  outside.  When 
the  cement  has  hardened  the  window  is  also  water- 
proof. 

Casement  Windows 

In  spite  of  the  greater  convenience  of  the  double- 
hung  windows,  the  older  casement  type  is  considered 
more  artistic  for  many  styles  of  architecture  and  has 
now  come  into  quite  general  use.  These  casement  win- 
dows are  swung  on  hinges  like  doors  and  are  made  of 
small  panes  of  glass,  sometimes  set  in  a  framework  of 
wood,  sometimes  leaded,  that  is,  put  together  with 
strips  of  lead  either  in  simple  squares  or  diamonds  or 
in  fancy  patterns. 

French  Windows 

French  windows  extend  to  the  floor  like  double  doors. 
They  often  open  on  porches,  but  sometimes  only  onto  an 
iron  grill  on  the  outside  of  the  base.  French  windows 
may  have  a  single  narrow  pane  of  glass.  They  are 
characteristically  high  and  narrow. 


I 


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GLASSWARE  DEPARTMENT 


English  Casement  Windows 

English  casement  windows  are  broad  in  proportion 
to  their  height  with  high  sills  and  are  usually  grouped 
two  or  three  in  a  row.  When  the  framework  of  these 
windows  is  of  wood  it  is  made  in  the  factory  in  the 
ordinary  way,  except  that  it  has  additional  cross-pieces 
and  smaller  panes . 

Leaded  Lights 

When  window  glass  is  set  in  lead  the  construction  is 
not  quite  so  simple.  The  lead  for  these  windows  is 
drawn  by  hydrostatic  presses  into  long  strips  with  a 
cross-section  like  the  letter  *'H."  (For  metal  drawing, 
see  ''Housefurnishings  Manual.")  There  are  over  a 
hundred  varieties  of  lead  strips  but  all  of  them  have 
a  similar  cross-section  with  two  broad  pieces  or 
"flanges"  connected  by  a  narrow  "heart."  The  width  of 
the  flanges  ranges  from  i/8  to  i  inch  and  the  hearts 
also  vary  according  to  the  thickness  of  the  glass  to  be 
inserted.  The  hearts  are  sometimes  made  of  steel  to 
give  greater  stiffness,  but  the  lead  is  then  much  harder 
to  bend  and  manipulate. 

A  window  made  of  leaded  lights  is  glazed  on  a  flat 
table  or  bench.  Two  strips  of  lath  are  first  placed  so 
that  they  form  a  perfect  right  angle,  and  are  securely- 
fastened.  This  angle  serves  as  the  corner  from  which 
the  window  is  built  up.    The  leads  ar^  then  straightened 


Windows  and  window  glass 


155 


in  a  small  vice  and  the  flanges  are  opened  with  a  wooden 
tool  to  admit  the  glass.  If  the  latter  is  cut  in  squares 
or  diamonds  the  glazing  is  done  with  long  straight 
pieces  of  lead  running  perpendicularly  or  at  the  same 
angle  with  the  line  used  as  a  base  and  short  pieces  of 
equal  length  for  the  intersecting  sides.  In  elaborate 
patterns  the  leads  may  need  a  great  deal  of  bending 
and  manipulation,  requiring  the  skill  of  a  trained  crafts- 
man. 

When  the  glass  has  been  placed  in  position  it  is 
secured  with  bench  nails  until  the  leads  are  applied, 
then  another  row  is  built  in  the  same  way.  Finally  the 
outer  leads  are  laid  on,  two  more  laths  are  nailed 
against  them,  and  the  joints  are  all  soldered  on  one 
side.  It  is  then  carefully  turned  over  and  soldered  on 
the  other  side  and  a  cement  made  of  white  lead,  linseed 
oil,  and  putty  is  brushed  into  all  the  cracks  and  joints  to 
make  them  water-proof. 

Kinds  of  Glass  Used  in  Leaded  Lights 
Colorless  glass  appears  as : 

Crown  glass,  which  is  made  by  a  spinning  process 
and  is  in  the  shape  of  discs  about  4  feet  in 
diameter  marked  with  concentric,  wavy  lines. 
The  heavy  centers  of  these  discs  are  called  "bull's 
eyes." 

Rippled  glass,  which  has  a  wavy  surface. 


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GLASSWARE  DEPARTMENT 


Embossed,  engraved,  or  etched  glass  (see  Chapter 
VII). 

Brilliant  cut,  on  plain  or  frosted  surfaces. 
Beveled  and  figured  glass. 

Colored  glass  may  be : 

Pot  metal  color,  either  solid  or  streaked  by  dipping 
the  blow  pipe  into  pots  of  different  colors  and 
working  them  together. 

Flashed  glass  (see  page  io6). 

Opalescent  glass  (see  page  103). 

Antique  glasses. 

Color  may  also  be  applied  in  the  form  of : 

Painted  enamels  and 
Silver  stain. 

All  of  these  colors  are  described  in  connection  with 
the  treatment  of  stained  glass. 

Colored  glass  is  used  in  mosaic  patterns  with  the 
figures  opalescent  but  studded  with  jewels  of  trans- 
parent color.  A  medieval  fashion  has  recently  been 
revived,  consisting  of  transparent  leaded  panes  with 
small  unsymmetrical,  painted  insets  representing  scenes, 
heraldic  devices,  or  other  symbols. 

Much  of  the  domestic  painted  or  opalescent  glass  is 
raw  in  color,  ugly  in  design,  and  inappropriate  to  its 
setting.  The  poor  quality  of  the  glass  and  the  crude 
designs  have  brought  it  into  disfavor  as  the  barest 


Courtesy  of  Pittsburgh  Art  Glass  Co. 
Figure  1 1 .     Leaded  Glass 


WINDOWS  AND  WINDOW  GLASS 


157 


simplicity  is  better  than  decoration  badly  done.  There 
are,  however,  many  opportunities  for  beautiful  work, 
entirely  suited  to  its  setting.  Uncolored  leaded  glass  of 
simple  pattern  can  hardly  go  wrong,  but  when  color  or 
pattern,  or  both,  are  added  they  must  be  handled  with 
taste,  some  knowledge  of  color  and  design,  and,  if 
possible,  an  acquaintance  with  the  history  and  develop- 
ment of  glass  decoration. 

Figure  11  is  a  good  example  of  domestic  leaded 
lights,  simple  in  treatment. 

History  of  Window  Glass 

To  our  comfort-loving  minds  one  of  the  most  im- 
portant uses  of  glass  is  in  windows  where  its  trans- 
parency or  translucency  admits  light  into  our  homes 
while  shutting  out  the  air.  In  warm  climates  this  is 
not  so  important,  however,  and  we  therefore  find  no 
evidences  of  the  use  of  glass  for  this  purpose  in  the 
Far  East  or  in  Egypt,  though  it  was  set  as  jewels  or 
ornaments  in  their  brass  or  stone  work. 

There  are  remains  of  glass  windows  in  the  ruins  of 
Herculaneum  and  Pompeii  and  those  of  Roman  villas 
in  Britain,  but  only  the  very  rich  could  afford  such  a 
luxury.  The  openings  in  medieval  castles  were  closed 
with  wooden  shutters  and  covered  with  draperies,  but 
in  the  homes  of  burghers  in  the  towns,  glass  was  gradu- 
ally introduced.     In  the  ninth  century  glass  was  used 


1/ 


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GLASSWARE  DEPARTMENT 


!. 


in  churches  and  domestic  fashions  seem  to  have  fol- 
lowed the  ecclesiastical  ones  except  that  the  treat- 
ment was  simpler,  and  more  transparent  glass  was 

used. 

The  finest  domestic  glass  was  made  in  Switzerland  in 
the  seventeenth  century.     This  glass  consisted  chiefly 
of  small  panels  exquisitely  painted  in  miniature  with 
enamel  colors.     Miniature  painting  on  glass  became 
the  national  art  of  Switzerland,  where  it  held  its  own 
for  a  century  after  it  had  been  lost  or  degraded  in  the 
rest  of  Europe.     Picture  panels  which  were  made  for 
wedding  gifts  or  exchanged  by  trade  guilds  are  now 
preserved  in  museums,  especially  the  one  at  Lucerne. 
The  favorite  subjects  were  the  exploits  of  the  family  or 
their  coats  of  arms,  which  had  become  exceedingly 
elaborate  in  the  seventeenth  century.     Some  of  our 
modern  houses  have  revived  this  use  of  coats  of  arms 
in  hall  windows  where  the  bright  colors  are  at  least 
pleasing  to  the  eye,  whether  anybody  knows  what  they 

mean  or  not. 

For  many  years  the  makers  of  window  glass  were 
interested  only  in  perfecting  their  processes  and  de- 
veloping a  clear,  flawless  glass,  but  the  time  came  when 
artists  condemned  this  mechanically  perfect  glass  as 
entirely  lacking  in  beauty.  Windows  made  with  such 
material  were  only  transparent  squares  in  the  wall  to 
which  they  added  no  charm  either  of  color  or  form. 


WINDOWS  AND  WINDOW  GLASS 


159 


Stained  Glass 

All  glass  colored  in  the  batch  might  be  called 
"stained,"  but  the  term  "stained  glass"  is  usually  under- 
stood to  refer  to  the  glass  found  in  church  or  memorial 
windows.  The  art  of  stained  glass  includes  design  as 
well  as  material. 

There  are  at  the  present  time  several  conflicting 
theories  concerning  this  form  of  art  glass,  which  can 
be  fully  appreciated  only  by  artists  but  are  of  interest 
to  everyone  interested  in  glass.  The  men  and  women 
who  have  the  choosing  of  church  windows  should  be 
able  to  distinguish  between  the  diflFerent  styles,  even  if 
they  are  not  artists. 

The  three  types  of  modern  stained  glass  windows  are : 

Enamel-painted 

Opalescent 

Antique 

Sometimes  all  three  are  to  be  found  in  one  church, 
giving  a  unique  effect,  but  not  one  to  be  commended. 
The  enamel-painted  window  is  the  one  most  widely 
used,  but  it  is  believed  by  many  artists  to  be  a  passing 
style.  The  two  other  types  are  the  result  of  efforts  to 
treat  glass  in  a  more  characteristic  way,  but  they  pro- 
ceed in  almost  opposite  directions,  differing  not  only  in 
the  treatment  of  the  glass  but  also  in  the  effects 
sought. 


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GLASSWARE  DEPARTMENT 


Enamel-Painted  Windows 

Enamel-painted  windows  have  been  the  generally  ac- 
cepted type  since  the  seventeenth  century  and  have  no 
clear  theory  of  glass  design.  They  are  made  of  colored 
glass  pieces  separated  by  lead  lines,  but,  except  in 
simple,  geometrical  patterns,  the  leads  are  not  of  great 
importance. 

The  more  elaborate  windows  are  heavily  painted  with 
enamels,  that  is,  with  metallic  paints  mixed  with  a 
flux  to  make  them  adhere  to  the  glass.  The  effects 
sought  are  similar  to  those  in  other  paintings  and  the 
artists  have  learned  the  painter's  technique.  Sometimes, 
in  order  to  give  the  desired  perspective,  deep  shadows 
and  heavy  masses  of  color  are  used,  which  make  the 
glass  practically  opaque. 

Eminent  artists  have  painted  these  pictures  and  the 
designs  are  often  beautiful,  but  they  are  not  true  "glass 
pictures."  They  suffer  from  the  use  of  a  method  which 
belongs  to  pictures  intended  to  be  looked  at  rather  than 
through  and  they  do  not  bring  out  the  beaut}  of  the 
glass. 

Opalescent  Windows 

Opalescent,  or  Tiffany,  windows  are  the  result  of 
many  experiments  made  by  the  artist,  John  La  Farge, 
and  further  developed  by  Louis  C.  Tiffany,  who  tried 
to  create  a  new  art  of  glass,  stained  in  the  batch  instead 
of  being  superficially  painted  (see  page  119)- 


WINDOWS  AND  WINDOW  GLASS  161 

The  material  is  very  beautiful,  with  an  exquisite 
blending  of  colors,  delicate  shading,  and  iridescence  pro- 
duced by  the  combinations  of  rich,  metallic  oxides  and 
remarkable  effects  of  line  and  form  made  by  the  skilful 
manipulation  of  the  glass  in  its  molten  state.  (See 
Chapter  XIII,  ^Tiffany  Favrile  Glass.") 

Antique  Glass  Windows 

Antique  windows  are  the  result  of  a  study  of  the 
early  art  of  stained  glass.  They  are  made  of  trans- 
parent colored  glials  and  are  therefore  nearer  the 
enameled  windows  than  the  opalescent,  but  the  only 
pigment  used  on  them  is  peroxide  of  iron  without  a 
flux.  This  is  sometimes  replaced  by  peroxide  of 
manganese.  If  the  former  is  used  it  gives  a  brown 
shading  while  the  manganese  is  black  but  no  new  color 
is  added  by  either  one.  They  only  serve  to  give  detail 
to  the  picture  outlined  by  the  leads  and  to  lower  the 
Hght.  According  to  an  old  proverb,  "The  glass  work- 
er's palette  is  his  glass." 

Antique  Glass 

The  making  of  stained  glass  like  that  of  the  thirteenth 
and  fourteenth  centuries  has  been  considered  one  of  the 
lost  arts,  because  glass  of  such  richness  and  variety  of 
color  and  depth  of  tone  was  supposed  to  have  been  made 
by  processes  of  which  the  secret  had  been  lost. 


II 


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GLASSWARE  DEPARTMENT 


This  is  not  the  fact.  The  beauty  of  the  old  glass  was 
not  due  to  secret  formulas.  On  the  contrary  its  variety 
of  color  and  texture  was  largely  the  result  of  imper- 
fections in  the  glass !  The  modern,  commercially  per- 
fect glass  with  which  we  are  familiar  is  too  uniform 
for  the  glassworker's  purpose. 

The  old,  crude  methods  of  manufacture  were  most 
uncertain  as  to  product.  The  various  metallic  oxides 
produce  different  results  at  different  furnace  tempera- 
tures and  sudden  variations  in  temperature  will  have 
strange  effects. 

Air  bubbles  and  impurities  were  the  result  of  crude 
methods  of  fining  and  variations  in  thickness  were  due 
to  other  limitations.  We  do  not  know  whether  the  old 
glassworkers  appreciated  the  value  of  these  imperfec- 
tions which  were  sometimes  serious  enough  to  mar  the 
beauty  of  the  metal,  but  often  had  the  opposite  effect. 
Air  bubbles  or  dust  when  seen  against  the  light  became 
prismatic,  refracting  the  rays  of  light  like  the  inner 
facets  of  jewels  and  giving  to  the  glass  a  crystalline 
quality  which  it  ordinarily  lacks. 

Streaks  of  color,  clouded  effects,  and  uneven  thick- 
ness were  variations  which  added  much  to  the  possibili- 
ties of  the  color  scale  and  the  craftsman  of  that  day 
added  to  these  unsought  variations  the  mixing  of  colors 
on  the  blowpipe,  flashing  the  metal  from  one  pot  on  that 
of  another,  and  other  devices  for  producing  the  effect 


WINDOWS  AND  WINDOW  GLASS 


163 


he  wanted.  His  greatest  allies,  however,  were  the 
lead  lines  which  gave  to  each  of  his  strong,  pure  colors 
its  greatest  intensity  and  to  the  whole  picture  its 
wonderful  brilliancy. 

Reproductions  of  Antique  Glass 

When  artists  began  again  to  use  the  strong  lead  lines 
and  to  aim  at  true  glass  technique,  they  also  tried  to 
reproduce  the  metal  of  the  old  craftsman.  In  this  effort 
they  have  been  more  than  successful.  It  is  now  pos- 
sible to  get  air  bubbles  and  streaks  and  cloudiness  by 
scientific  methods  instead  of  depending  on  accident. 

The  best  antique  glass  is  of  English  manufacture. 
It  is  all  made  by  hand  and  each  successful  variety  has 
back  of  it  many  costly  experiments.  For  this  reason  the 
maker  must  have  the  promise  of  support  in  his  venture 
and  thus  far  the  United  States  has  not  given  this 
promise.  Windows  in  this  country  are  a  combination 
of  the  flat-toned  domestic  and  imported  antique  glass, 
the  latter  being  used  for  the  more  brilliant  effects. 

Antique  glass  is  usually  blown  in  cylinders  and  then 
flattened  into  sheets  24  inches  long  and  16  inches  wide. 
One  variety  called  "Venetian"  is  blown  into  a  mold  hav- 
ing a  screw  pattern  on  the  inner  surface.  While  still 
soft  it  is  removed  to  another  mold  having  the  screw 
pattern  running  in  the  opposite  direction  so  that  the 


164 


GLASSWARE  DEPARTMENT 


intersecting  lines  produce  lozenges  which  are  used  as 
jewels. 

Color  is  flashed  on  a  colorless  base,  as  in  ruby  glass, 
which  is  always  made  in  this  way,  or  it  may  be  on 
another  color,  gold  pink  (made  with  gold  oxide)  being 
flashed  on  yellow,  blue,  or  purple  to  make  certain  very 
brilliant  colors. 

A  glass  similar  to  the  antique,  called  "Norman  slab," 
is  colorless,  or,  rather,  a  greenish  white.  It  is  blown 
into  a  mold  shaped  like  an  iron  box,  which  chills  the 
metal  so  quickly  that  it  spreads  over  the  mold  very  un- 
evenly, producing  a  wavy  appearance  like  water. 

The  Making  of  Stained  Glass  Windows 

Like  architecture,  with  which  it  has  a  very  close  con- 
nection, stained  glass  is  both  an  art  and  a  craft.  It 
begins  with  the  design  of  the  artist,  but  it  ends  with  the 
very  practical  art  of  glazing.  Windows  are  openings 
through  which  a  building  is  lighted  and  therefore 
should  be  wind-proof  and  rain-proof,  but  not  light- 
proof,  as  some  unfortunately  are. 

The  process  of  constructing  a  window  involves  many 

minor  operatons.     These  may  be  grouped  as  follows : 

I.  Making  the  small  colored  design.     For  picture 

windows  there  are  two  additional  stages  in  this  first 

process : 


WINDOWS  AND  WINDOW  GLASS  165 

(a)  Making  figure  studies 

(b)  Drawing  large  cartoons 

2.  Making  the  large  "cut  line"  drawings  indicating 
the  position  of  the  leads.  The  sections  of  these  draw- 
ings are  all  numbered. 

3.  Cutting  out  the  sections  with  pattern  shears,  which 
are  three-bladed,  leaving  a  space  for  the  leads. 

4  Laying  each  section  on  glass  of  the  color  desired 
and  cutting  the  glass  with  a  steel  wheel  (instead  of  a 
diamond  as  it  was  formerly  done).  For  enamel-painted 
windows  only  the  ground  color  is  needed.  In  antique 
windows  the  pieces  are  smaller  and  there  is  great  care 
taken  to  choose  those  of  exactly  the  right  texture  and 
color  gradations.  For  opalescent  windows  the  choice  in- 
volves not  only  color  but  lines  and  suggestions  of  form, 
as  the  picture  is  to  be  a  glass  mosaic.  If  the  right  effect 
is  not  secured  by  the  first  choice  the  glass  may  be 
"plated,"  with  one  piece  on  top  of  another. 

5  The  pieces  are  next  assembled  on  a  glass  easel  for 
the  purpose  of  completing  the  design.  They  are  tem- 
porarily attached  to  this  easel  with  wax. 

6  Enamel-painted  windows  are  now  ready  for  the 
completion  of  the  design.  As  the  different  colored 
enamels  are  not  of  the  same  composition  they  do  not 
-fire"  at  the  same  temperature  and  the  heat  necessary 
to  fuse  one  color  on  the  glass  would  melt  another  one 
completely.     They  must  therefore  have  the  harder 


l66 


GLASSWARE  DEPARTMENT 


enamels  put  on  and  fired  first  and  the  softer  ones  later. 
Antique  windows  are  painted  in  a  similar  way  except 
that  the  pigment  is  without  variation  of  color  or  flux. 
The  method,  however,  is  quite  different  because  the 
effect  is  to  be  flat.  The  design  is  worked  over  several 
times,    always    with    iron   peroxide,    called    "antique 

brown." 

First,  the  outlines  are  drawn  in  with  the  pigment 
mixed  with  French  fat  oil  and  turpentine.  The  whole 
design  is  then  stippled  over  with  a  soft  badger  brush, 
the  pigment  being  mixed  with  water  and  gum  arable. 
This  is  rubbed  down  to  give  shading  and  high  lights, 
the  glass  is  given  a  coating  of  coal  oil  and  the  design 
again  strengthened  and  softened  by  the  application  of 
the  pigment  ground  in  oil  of  tar  and  coal  oil.  Both 
hard  and  soft  brushes  are  used,  some  of  them  very  finely 
pointed  and  with  handles  having  sharp  metallic  points 
with  which  the  color  may  be  cut  away. 

Some  of  the  best  work  is  a  combination  of  etching 
and  painting.  Flashed  glass  is  used  which  has  the 
upper  layer  cut  away  in  certain  places,  exposing  the 
color  beneath  and  this  coat  may  be  further  varied  with 
a  coat  of  silver  stain. 

Silver  Stain 

This  is  the  one  true  stain  used  on  all  kinds  of  stamed 
glass.     It  is  made  of  a  solution  of  silver  which  gives 


WINDOWS  AND  WINDOW  GLASS 


167 


the  glass  a  beautiful  series  of  yellows  from  a  pale, 
greenish  shade  to  a  deep  orange,  without  destroying  its 

transparency. 

Opalescent  glass  also  must  have  certain  features 
painted,  such  as  the  faces,  hands,  and  feet  of  persons 
in  the  pictures,  but  it  cannot  be  fired  without  losing  its 
play  of  color  and  iridescence. 

Firing 

Glass  was  formerly  put  in  a  muffle  or  closed  kiln  for 
firing,  in  order  that  it  might  be  protected  from  the 
fumes  and  smoke  of  the  fuel.  Small  gas  furnaces  are 
now  used.  The  best  kilns  are  tunnel-shaped,  about  8 
feet  long  and  3  feet  wide,  with  an  arched  roof  2  1/2  feet 
high  in  the  center.  The  glass  rests  on  an  asbestos- 
covered  tray  on  each  side  of  which  is  a  series  of  gas 
jets  which  may  be  turned  on  and  off  either  separately 
or  at  the  main  key. 

Firing  in  a  gas  kiln  takes  from  half  an  hour  to  an 
hour  and  a  half.  If  the  results  are  not  satisfactory  the 
process  is  repeated. 

Glazing 

Glazing  is  the  final  assembling  of  the  window.  Two 
straight  pieces  of  wood  are  placed  at  right  angles  on 
the  glazier's  bench  and  securely  fastened,  forming  the 
corner  from  which  the  window  is  to  be  put  together. 


i68 


GLASSWARE  DEPARTMENT 


The  leads  are  stretched  and  straightened  and  clipped 
into  suitable  lengths  and  the  outside  leads  are  laid 
against  these  laths. 

The  working  drawing  is  placed  on  the  board  and, 
row  after  row,  the  glass  is  set  in  place  with  leads  be- 
tween. At  intervals  pieces  of  wire  are  soldered  in 
which  are  afterwards  twisted  around  tie  bars. 

The  antique  window  designs  need  the  leads  which  are 
of  several  different  widths,  some  of  them  quite  broad. 
The  glass  in  these  windows  is  in  small  pieces,  and  if 
the  leads  were  not  part  of  the  design  they  would  mar  it. 

In  the  painted  windows  the  leads  are  not  an  important 
part  of  the  design,  and  in  the  opalescent  they  are  still 
more  inconspicuous. 

When  the  assembling  is  completed  the  joints  are 
coated  with  oleic  acid  and  soldered  on  both  sides. 
Finally  a  cement  made  of  white  lead,  linseed  oil,  and 
putty  is  brushed  into  the  spaces  between  the  leads  and 
the  glass  and  worked  down  into  the  cracks  until  the 
window  is  water-proof. 

Stained  glass  windows  assume  one  of  two  following 
forms: 

Lancet,  high,  narrow,  and  pointed  at  the  top  like  a 

lance. 
Rose  or  circular. 

The  windows  may  be  divided  into  sections  by  stone 
mullions. 


WINDOWS  AND  WINDOW  GLASS 


169 


Effect  of  the  Finished  Window 

The  beauty  of  a  stained  glass  window  is  very  much 
affected  by  its  location.  Those  which  are  to  be  placed 
nearly  on  a  level  with  the  eye  can  be  given  delicate 
treatment,  but  those  to  be  seen  at  a  distance  must  be 
given  bold  lines  or  the  design  will  be  weak  and  blurred. 
The  lines  are  not  only  softened  by  distance  but  the  light 
which  shines  through  the  glass  is  refracted  so  that  it 
narrows  even  the  leads.  Work  which  may  seem  harsh 
and  crude  on  the  easel  is  only  strong  and  well  defined 
at  the  proper  distance. 

The  effect  of  light  is  all-important.  Windows  with 
"hot"  colors  should  not  be  on  the  south  side  of  -the 
building  to  receive  the  glare  of  a  summer  sun,  but 
against  a  cool,  gray  light.  The  brilliancy  of  adjoining 
windows  and  the  lights  which  will  fall  across  the 
picture,  must  also  be  considered. 

The  artist  who  is  to  design  the  window  should  al- 
ways see  its  setting.  Otherwise  he  cannot  know  all  of 
these  points.  Drawings  and  photographs  may  indicate 
the  architecture  of  the  building,  but  cannot  give  an 
idea  of  color  and  light. 

Stained  Glass  Design 

Enamel-painted  and  opalescent  windows  are  alike  in 
one  respect.  They  are  intended  to  look  like  pictures. 
Rounded  forms,  shadows,  and  perspective  give  one  the 


II 


170 


GLASSWARE  DEPARTMENT 


sense  of  looking  through  the  window  at  a  scene  beyond. 
The  pictures  are  often  beautiful,  but  they  are  not  archi- 
tectural in  design,  as  wall  decorations  should  be,  and 
they  sadly  obscure  the  light. 

In  this  respect  the  opalescent  glass  is  an  even  greater 
offender  than  that  which  is  painted  in  enamels.  The 
large  quantities  of  metallic  oxides  and  the  creases  and 
ridges  which  look  so  like  drapery  or  landscapes  are  too 
heavy  to  be  translucent.  These  mosaics  are  seen  at  their 
best  only  when  there  is  a  cross-light  or  when  the  build- 
ing is  otherwise  illuminated  than  by  the  windows. 

Antique  windows  are  not  paintings  in  the  ordinary 
sense,  that  is,  they  do  not  attempt  the  painter's  effects 
of  perspective.  The  strong  leaded  lines  enclosing  their 
fragments  of  color  give  to  the  artist  a  material  which 
is  quite  unique.  Not  form  or  even  color  is  the  basis  of 
this  art,  but  light. 

The  designs  in  antique  windows  are  not  massive  even 
when  the  space  to  be  filled  is  a  large  one.  One  of  the 
unfortunate  features  of  the  massive  designs  sometimes 
seen  is  that  they  dwarf  their  surroundings.  By  keep- 
ing the  designs  small,  the  apparent  height  of  the  window 
is  increased.  Grisaille  (or  grayish)  windows  have  a 
background  of  silvery  gray  with  suggestions  of  green, 
blue,  or  amber,  and  medallions  of  more  intense  colors 

set  against  it. 

The  glass  worker's  pigment  is  used  to  intensify  the 


{ 


Figure  I2.     A  Stained  Glass  Window 

The  Captain  Simpkins  memorial  window.  Church  of  St.  John  the  Evangelist, 
Beverly,  Mass.,  designed  and  made  by  Charles  J.  Connick 


WINDOWS  AND  WINDOW  GLASS  171 

effects  of  light  and  color  even  more  than  to  outline  the 
pattern.  It  is  heaviest  near  the  leads,  lowering  the  tone 
of  the  light  and  preventing  its  refraction  across  them. 
From  the  leads  it  shades  off  gradually  to  a  point  of 
greatest  clearness  and  brilliancy  near  the  center  of  the 

glass. 

On  the  other  hand  the  design  itself  is  almost  m 
silhouette ;  the  shadows  are  indicated  by  differences  in 
color  tone  rather  than  with  pigment. 

In  Gothic  architecture  the  leads  are  often  but  a  con- 
tinuation of  the  stone  traceries  in  which  the  windows 
are  set  and  the  painted  outlines  have  the  effect  of  a 
finer  series  of  leads,  while  each  piece  of  glass  is  treated 
in  such  a  way  as  to  bring  out  all  its  color  values. 

Since  windows  are  usually  seen  at  a  considerable 
distance  the  color  makes  its  impression  before  any  de- 
sign can  be  seen.  If  the  distance  is  great  the  design 
may  not  be  clearly  seen  at  all,  the  window  is  only  a 
group  of  color  spots  or  color  masses. 

In  one  modern  Gothic  church  the  most  beautiful 
window  is  behind  the  organ  where  only  a  suggestion  of 
its  design  can  be  seen.  But  no  person  can  enter  the 
church  without  having  his  attention  arrested  by  the 
shafts  of  intense  blue  light,  like  blue  fire  behind  the 
silver  gray  organ  pipes. 

Figure  12  is  an  example  of  a  lancet  wmdow  with  the 


172 


GLASSWARE  DEPARTMENT 


background  in  grisaille  and  the  central  figure  and  the 
side  panels  in  rich  but  clear  colors.  The  lead  lines  form 
a  part  of  the  pattern.  In  the  small  panes  are  symbolic 
pictures. 


Part  IV— The  Glass  Industry 


Chapter  XVUI 

HISTORY  OF  GLASS-MAKING 

Wonders  of  Glass-Making 

"  Among  the  discoveries  due  to  chance  and  perfected 
by  man's  intellect,  the  invention  of  glass  is  certainly  one 
of  the  most  important.  Two  examples  taken  from 
two  extremes  of  creation,  the  infinitely  great  and  the 
imperceptibly  small,  will  sufficiently  prove  this  —  the 
telescope,  which  brings  the  heavenly  bodies  within  the 
range  of  the  astronomer's  study,  and  the  microscope, 
which  may  be  said  to  be  still  more  useful."  ^ 

Glassmakers  of  Egypt 

The  ancient  Egyptians  were  workers  in  glass  as  they 
were  in  pottery  and  many  other  arts. 

The  first  evidence  of  the  domestic  use  of  glass  is 
found  in  the  frescoes  of  Thebes,  and  on  some  of  the 
earliest  tombs  glassblowers  are  represented.  Many 
remnants  of  Egyptian  glass,  all  beautifully  iridescent 
with  earth-made  colors,  have  been  found  also  in  ruins 

1  Wonders  of  Glass-making.    Sauzay. 

173 


« 


174 


GLASSWARE  DEPARTMENT 


HISTORY  OF  GLASS-MAKING 


175 


off  buried  palaces  which  have  been  excavated. 
The  Egyptians  made  many  articles  of  a  deep,  trans- 
parent blue  glass,  using  it  for  small  vases,  mosaics, 
beads,  imitation  stones,  scarabs,  bracelets,  scent  bottles, 
and  charms.  Less  often  they  colored  their  ornaments 
with  pale  buff,  deep  green,  and  in  rare  cases  with  red. 
Sometimes  the  piece  was  decorated  with  bands  of 
white,  yellow,  or  turquoise  blue,  and  in  some  instances 
the  whole  surface  was  colored.  Birds  in  mosaics  are 
said  to  have  been  represented  with  such  accuracy  and 
delicacy  of  detail  that  each  separate  feather  of  wing 
and  tail  could  be  easily  distinguished.  In  the  British 
Museum  is  a  human-headed  hawk  not  exceeding  three- 
fourths  of  an  inch  in  its  greatest  dimension.  Other 
examples  characteristic  of  Egyptian  skill  in  the  art  of 
glass-making  are  specimens  of  beautiful  glass  jewelry 
found  in  Memphis  and  now  at  the  Salle  Historique  at 
the  Louvre,  and  a  yellow  glass  scent  bottle  with  the 
name  in  blue  glass.  In  the  British  Museum  is  an  ex- 
quisite little  blue  and  orange  glass  bottle  bearing  the 
name  of  Thothmes  II  (eighteenth  dynasty,  about  1590 
B.C.);  and  in  the  Bulak  Museum  is  an  elaborate 
bracelet  found  in  the  tomb  of  the  mother  of  one  of  the 
kings  of  the  eighteenth  dynasty.  It  is  formed  of 
microscopic  gold,  red,  and  blue  glass  beads,  strung  on 
fine  gold  wire  in  a  symmetrical  design  of  triangles. 


Theban  Works  of  Art 

Some  of  the  cups  of  varied  colors  found  in  Thebes 
show  great  skill  in  what  may  be  called  glass-porcelain, 
usually  in  blue  or  green.  Both  the  molding  and  the 
cutting  of  glass  were  also  practiced  there,  as  shown  in 
figures  and  ornaments  cast  in  a  mold,  and  in  vases  and 
beads  engraved  in  various  designs. 

Glass  of  Other  Oriental  Countries 

Glass  was  also  made  in  India  and  in  China,  but  the 
Indian  glass  was  very  defective  and  Indian  methods 
were  primitive.  The  Chinese  probably  copied  the 
methods  of  the  Phoenicians,  but  most  of  their  glass 
was  in  imitation  of  precious  stones. 

Assyrian  Workmanship 

Quantities  of  small  glass  articles,  such  as  amulets, 
were  early  exported  from  Egypt  to  Assyria.  The  As- 
syrians understood  the  glazing  of  pottery  and  did 
much  of  it,  as  we  learn  from  their  ornaments  and  their 
glazed  architectural  bricks.  The  first  specimen  of 
their  glass  was  a  vase  found  in  Nineveh,  inscribed  with 
the  name  of  an  early  king;  while  a  greenish  glass  bowl 
found  in  1852  bears  the  name  of  Sargon  (722  B.C.)  -— 
that  is,  in  the  eighth  century  B.C.  This  vase  is  now  in 
rhe  British  Museum.     It  is  supposed  to  be  the  oldest 


176 


GLASSWARE  DEPARTMENT 


HISTORY  OF  GLASS-MAKING 


177 


M 


specimen  of  transparent  glass  yet  discovered ;  as  those 
from  Egypt  appear  to  belong  to  a  period  earlier  than 
the  sixth  or  seventh  century  b.  c.  The  Sargon  vase 
Was  blown  in  one  solid  piece  and  then  hollowed  out  and 
shaped  by  a  turning  machine.  Two  larger  vessels  of 
alabaster  were  found  with  it  and  all  were  probably 
used  for  holding  ointment  or  perfume.  A  rock  crystal 
lens  was  also  found,  supposed  to  have  been  ground  on 
a  lapidary's  wheel  and  to  have  been  used  as  a  mag- 
nifying glass.  Blue  glazed  pottery,  glass  bottles,  and 
other  vases  of  elegant  shape,  some  of  them  decorated 
in  gilt,  were  unearthed  at  the  same  time. 

Persian  Glassware 

Persia  also  produced  some  beautiful  glass,  specimens 
of  which  may  be  found  in  the  British  Museum  and 
other  collections ;  but  Tyre  and  Sidon  were  the  cities 
most  celebrated  for  glass-making. 

According  to  an  old  legend,  sailors  from  a  Tyrian 
ship  carrying  a  cargo  of  niter,  went  on  shore  to 
eat.  Finding  no  stones  upon  which  to  place  their  pot, 
they  set  it  upon  blocks  of  niter,  and  used  seaweed  for 
fuel.  When  the  fire  died  down  they  discovered  that 
the  niter  had  melted  and,  fusing  with  the  sand  and  the 
ashes  of  the  seaweed,  had  made  glass.  Whether  this 
story  is  fact  or  fable,  it  is  certain  that  the  glass  fac- 


tories of  this  enterprising  group  of  merchants  were 
noted  up  to  and  during  Roman  times. 

Sidon  is  said  to  have  invented  glass  mirrors  and  to 
have  known  the  value  of  manganese  in  making  glass 
clear. 

We  know  that  Phoenician  citizens  used  the  blowpipe 

and  the  graver. 

Characteristics  of  Grecian  Glass 

Greece,  which  excelled  in  pottery,  paid  little  atten- 
tion to  glass-making.  The  Greeks  in  Rhodes  produced 
glass  vessels,  such  as  small  bowls  of  clear  crystal  and 
harmonious  colors.  Bottles  of  opaque  blue  or  green 
decorated  with  gold  have  been  found  in  Grecian  tombs. 
As  a  rule  the  Greeks  preferred  the  blue  or  crystal  glass. 
Grecian  articles  of  glass  must,  however,  have  been 
largely  imported,  since  there  is  no  trace  of  the  manu- 
facture of  glass  on  Greek  soil. 

Roman  Glass 

The  Romans  used  glass  extensively  for  domestic 
and  architectural  purposes  and  also  for  personal  adorn- 
ment. Factories  were  established  as  early  as  the  first 
century  a.d.  The  emperor  Nero  was  a  great  lover 
of  glass  and  an  enthusiastic  collector,  and  by  his  ex- 
ample stimulated  the  rich  Romans  to  pay  extrava- 


i- 


178 


GLASSWARE  DEPARTMENT 


gant  prices  for  glass,  crystal,  and  murrine  (a  costly  ma- 
terial not  definitely  known)  vases  to  use  on  the  table 
at  their  banquets.  Through  the  encouragement  of  the 
royal  families  there  was  also  much  luxurious  ex- 
travagance in  toilet  and  perfume  bottles;  the  Roman 
ladies  and  their  slaves  carried  their  own  toilet  ap- 
paratus to  the  baths.  Mourners  gathered  their  tears 
in  tear-bottles  hardly  one-half  inch  in  height,  and 
placed  them  beside  the  ashes  of  their  friends ;  and  also 
poured  wine  and  milk  from  fancy  bottles  on  the  funeral 
pyres.  Some  of  these  funeral  and  tear-bottles  may  be 
found  in  the  Louvre.  Other  bottles  supposed  to  have 
been  intended  for  presents  are  engraved  with  the  pic- 
ture of  a  heart  and  the  word  "Amor."  Beautiful 
color  effects  were  obtained  from  the  use  of  green, 
blue,  purple,  amethyst,  amber,  brown,  and  rose,  in  both 
opaque  and  transparent  glass ;  some  eight  or  ten  shades 
of  blue  varying  from  lapis  to  turquoise  were  known. 

Varieties  of  Glassware 

There  were  also  many  styles  of  design  for  the  glass- 
ware, including  perfume,  cosmetic,  and  funeral  bot- 
tles, drinking  cups,  flasks,  bowls  and  other  vessels,  dice, 
mosaics,  small  ornaments,  and  especially  imitation 
stones;  the  latter  were  often  carved  as  intaglios  and 
cameos,  or  set  in  beautiful  filigree  work.     Cinerary 


A — Amphora  B   and    C — Ampullas  D— Vase 

Figure  13.    Examples  of  Roman  Molded  Glass 


m 


^ 


m 


178 


GLASSWARE  DEPARTMENT 


gant  prices  for  glass,  crystal,  and  murrine  (a  costly  ma- 
terial not  definitely  known)  vases  to  use  on  the  table 
at  their  banquets.     Through  the  encouragement  of  the 
royal    families   there   was   also  much   luxurious   ex- 
travagance in  toilet  and  perfume  bottles;  the  Roman 
ladies  and  their  slaves  carried  their  own  toilet  ap- 
paratus to  the  baths.     Mourners  gathered  their  tears 
in   tear-bottles  hardly  one-half   inch   in  height,   and 
placed  them  beside  the  ashes  of  their  friends ;  and  also 
poured  wine  and  milk  from  fancy  bottles  on  the  funeral 
pyres.     Some  of  these  funeral  and  tear-bottles  may  be 
found  in  the  Louvre.     Other  bottles  supposed  to  have 
been  intended  for  presents  are  engraved  with  the  pic- 
ture of  a  heart  and  the  word  "  Amor."     Beautiful 
color  effects  were  obtained  from  the  use  of  green, 
blue,  purple,  amethyst,  amber,  brown,  and  rose,  in  both 
opaque  and  transparent  glass ;  some  eight  or  ten  shades 
of  blue  varying  from  lapis  to  turquoise  were  known. 

Varieties  of  Glassware 

There  were  also  many  styles  of  design  for  the  glass- 
ware, including  perfume,  cosmetic,  and  funeral  bot- 
tles, drinking  cups,  flasks,  bowls  and  other  vessels,  dice, 
mosaics,  small  ornaments,  and  especially  imitation 
stones;  the  latter  were  often  carved  as  intaglios  and 
cameos,  or  set  in  beautiful  filigree  work.     Cinerary 


A— Amphora         B   and    C— Ampullas         D— Vase 
Figure  13.    Examples  of  Roman  Molded  Glass 


HISTORY  OF  GLASS-MAKING 


179 


ums  were  used.  Roman  ladies  carried  glass  balls  to 
cool  and  whiten  their  hands,  changing  the  ball  as  the 
glass  heated.  At  banquets  slaves  poured  wine  and 
water  from  large  carafes  or  decanters  into  the  drink- 
ing cups  of  the  guests. 

Glass  was  blown,  molded,  pressed,  and  cut.  The 
crystal  glass  made  by  the  Romans  was  clearer  and 
stronger  than  that  of  the  Egyptians,  and  so  like  the 
real  or  rock  crystal  as  almost  to  defy  detection. 

In  Figure  13,  A  shows  a  violet-colored  Roman  am- 
phora—  a  tall  two-handled  jar  —  which  was  used  to 
hold  wine  or  oil.  The  surface  has  decayed  and  has  the 
iridescence  found  in  most  ancient  glass.  It  is  encircled 
with  a  series  of  horizontal  alternate  narrow  flutings 
and  ribbons. 

Figure  B  portrays  an  ampulla,  a  vase  used  to  hold 
perfumes  and  oil.  It  is  made  of  opaque  light  blue 
glass  much  decayed,  molded  in  relief,  and  ornamented 
with  an  amphora,  a  diota  (two-handled  cup)  and  other 
vases  placed  between  six  columns  supporting  pointed 
arches.  Near  the  base  are  bunches  of  grapes  and  fes- 
toons. 

Figure  C  gives  an  illustration  of  another  ampulla. 
It  is  of  light  green  glass  with  the  surface  divided  by 
projecting  lines  into  6  compartments  containing  in  re- 
lief an  amphora,  a  syrinx  (Pan's  pipes),  a  patera  (a 


Mi 


m 


1 80  GLASSWARE  DEPARTMENT 

shallow  bowl  or  cup  used  for  pouring  libations),  and 
crossed  scepters;  above  these  compartments,  the  ves- 
sel is  fluted. 

Figure  D  represents  a  vase  of  dark  glass  much  de- 
cayed, upon  whfch  a  human  face  is  molded  in  relief. 

Glass  of  Pompeii  and  Herculancum 

Both  these  cities  have  yielded  varied  and  splendid 
examples  of  Roman  glass  now  stored  in  the  Bourbon 
Museum  of  Naples  and  elsewhere.  More  than  four 
thousand  such  articles  have  been  collected,  among 
them  the  Naples  and  Portland  vases  discovered  in  a 
tomb  in  1644  and  placed  in  the  British  Museum.  The 
Portland  vase  is  always  referred  to  as  the  most  beau- 
tiful known  specimen  of  the  glass  engraver's  skill.  It 
was  at  first  supposed  to  be  carved  from  a  precious 
stone,  but  on  closer  inspection  it  was  found  to  be  made 
of  a  dark  blue  glass  with  exquisite  cameo-like  figures 
which  are  carved  out  of  a  superimposed  layer  of 
opaque  white. 

Varieties  of  Bottles 

Among  the  Pompeiian  relics  are  numbers  of  square 
glass  bottles  in  which  housekeepers  kept  their  wine, 
oil,  vinegar,  honey,  etc.;  some  of  these  bottles  are  a 
foot  and  a  half  high,  while  there  are  hundreds  of 
smaller  bottles  of  other  types.     There  are  glass  plates 


HISTORY  OF  GLASS-MAKING  181 

fourteen  inches  across.     A  fragment  of  one  patera 
made  of  a  blue  glass  that  is  as  splendid  as  a  sapphire 
with  milk-white  cameos  on  it,  representmg  a  twig  ot 
ivy  leaves  enclosing  the  head  of  a  ram,  suggests  Pliny  s 
words,  *'  They  sculptured  glass  more  delicately  than 

silver." 

Other  Glassware 

Glass  cups,  called  Christian  glass,  in  colored  designs 
are  also  found  among  the  relics  of  the  catacombs  of 
Rome  The  subjects  pictured  are  religious,  such  as  the 
Nativity  and  the  raising  of  Lazarus.  Some  of  the  cups 
have  purple  in  the  draperies,  green  in  the  sea  waves, 
and  pink  in  the  faces,  while  the  more  ornate  specimens 
are  decorated  with  silver,  gold-leaf,  and  powdered 
gold  Little  crystal  glass  fish  are  also  found,  together 
with  vases  supposed  to  have  held  sacred  oils. 

Venetian  Glass 

Verv  little  is  known  of  glass  manufacture  in  Italy 
immediately  after  the  fall  of  the  Roman  Empire,  as  the 
industry  almost  died  out  with  the  removal  of  the 
government  from  Rome  to  Constantinople.  Some 
ftalian  refugees,  during  the  invasion  of  the  terrible 
Huns  under  their  leader  Attila,  fled  to  Venice,  where 
the  industry  was  kept  alive.  Among  these  refugees 
were  glassmakers,  who  about  the  fifth  century  started 


II 


\M 


182 


GLASSWARE  DEPARTMENT 


the  industry,  which  was  soon  to  become  one  of  the 
most  extensive  and  world  renowned  in  the  history  of 
glass-making.  The  marine  alkali-yielding  plants  and 
the  abundance  of  sand  about  Venice  had,  no  doubt, 
much  to  do  with  the  rapid  development  and  the  beau- 
tiful products  of  the  Venetian  glassmakers.  But  the 
Venetians  also  utilized  foreign  commodities.  Boats 
were  sent  to  Syria  to  collect  the  white  sand  for  which 
their  glassware  was  celebrated,  and  special  woods  were 
brought  from  great  distances. 

The  Emperor  Constantine  had  taken  expert  glass- 
makers  to  Constantinople,  but  the  fall  of  that  city  in 
1204  drove  many  Greek  workmen  back  to  Venice  with 
their  new  recipes  to  enrich  the  industry.  The  Vene- 
tians guarded  their  secrets  with  the  greatest  care.  If 
any  workman  carried  his  skill  to  another  city  he  was 
ordered  back  and  his  relatives  were  imprisoned  until 
he  came.  Glassmakers  were  highly  honored  and  many 
of  them  were  given  the  rank  of  nobles. 

Figure  14  shows  an  ancient  Venetian  glass  furnace 
with  the  glassblowers  at  work,  and  Figure  15  shows 
the  tools  used. 

Murano  a  Famous  Glass  Center 

In  1 29 1  fear  of  fire  drove  the  council  to  pass  laws 
abolishing  glass  furnaces  within  the  city,  and  the  glass- 
makers  were  driven  to  the  lagoon  island  of  Murano,  a 


t»« 


^^^^^^fe 


yi. 


A— Blowpipes         B— Glass   Pots         C— Working  Holes 
Figure  14.     Ancient  Venetian  Glass  Furnace 


HISTORY  OF  GLASS-MAKING 


183 


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1 84 


GLASSWARE  DEPARTMENT 


suburb  of  Venice,  which  has  been  a  famous  glass  center 
ever  since.  In  the  early  part  of  the  seventeenth  cen- 
tury there  were  three  hundred  glass  manufactories  in 
Murano,  and  nowhere  in  the  world  could  their  beau- 
tiful products  be  matched.  The  vases,  cups,  bottles, 
and  decanters  of  delicate  crystal  were  prized  by  kings 
and  often  were  more  costly  than  if  they  had  been  made 
of  gold. 

In  1300,  Murano  artists  began  to  coat  plates  of  glass 
with  an  amalgam  of  tin  and  mercury,  and  their  mir- 
rors became  the  standard  throughout  Europe.  In  1436 
they  began  to  use  color  in  glass ;  the  earlier  products 
were  clear  crystal  with  a  greenish  or  violet  tinge. 

Murano  made  the  most  beautiful  beads,  tableware, 
bric-a-brac,  and  the  beautiful  brown  glass  flecked  with 
brass  filings  known  as  aventurin.  Their  glass  was  soft 
so  that  it  could  be  spun,  woven,  or  fashioned  into  the 
daintiest  designs,  and  they  also  understood  that  the 
reheating  of  glass  added  brilliancy ;  a  single  piece,  it  is 
said,  was  heated  as  many  as  fifty  times.  To  the 
Murano  artists,  with  their  extreme  delicacy  of  taste 
and  touch  inherited  from  their  ancestors,  coupled  with 
endless  study  of  their  art,  may  be  ascribed  a  fame 
which  eclipsed  that  of  any  other  glass-making  center 
in  Italy,  so  that  for  a  long  time  Venetian  glass  enjoyed 
a  monopoly.  In  recent  years  there  has  been  a  revival 
of  the  skill  of  the  Venetian  craftsmen. 


li 


HISTORY  OF  GLASS-MAKING 


185 


Development  of  Art  in  Other  Countries 

The  development  of  glass-making  in  France,  Ger- 
many, and  England  in  the  seventeenth  and  eighteenth 
centuries  had  an  injurious  effect  on  the  industry  in 
Murano.  The  invention  of  flint  glass  was  a  serious 
blow  to  the  industry,  as  flint  glass  is  soft  and  heavy  and 
suitable  for  cutting,  while  the  light,  thin  Venetian  ware 
cannot  be  cut.  Glassmaking  in  Murano  declined  dur- 
ing the  eighteenth  century  to  such  an  extent  that  of 
300  factories  only  one  remained  in  the  early  part  of 
the  nineteenth  century. 

The  modern  renaissance  of  Venetian  glass  is  due  to 
the  efforts  of  C.  Pietro  Biguglia  (1845)  and  later  of 
Salviati,  who  revived  the  old  processes  and  invented 
others,  and  practiced  them  with  freedom  and  fine  ar- 
tistic instinct.  Backed  by  English  capitalists,  Biguglia 
reproduced  old  forms  of  Venetian  glass  and  exhibited 
it  at  industrial  expositions  with  conspicuous  success. 

Spanish  Glass 

Numerous  traces  of  early  glass  furnaces  are  found 
in  Spain,  a  result  no  doubt  of  the  spread  of  the  in- 
dustry from  Rome  throughout  her  provinces.  Small 
jars,  cups,  phials,  thickly  molded  saltcellars,  tear-bot- 
tles,' and  bracelets  found  in  tombs  suggest  home  manu- 
facture of  them  in  the  valleys  of  the  Pyrenees.  Much 
of  the  glass  of  Barcelona  (1324)  bears  a  resemblance 


1^1 


i\\ 


1 86 


GLASSWARE  DEPARTMENT 


to  the  old  Venetian  glass  and  seems  to  have  been  made 
both  for  home  and  export  use.  Many  beautiful  ex- 
amples of  Spanish  glass  are  found  in  the  South  Ken- 
sington Museum. 

Bohemian  Glass 

During  the  sixteenth  century  glass-making  in  Bo- 
hemia became  a  recognized  industry,  when  goblets  and 
tankards  of  white  glass  with  colored  coats  of  arms, 
millefiori  (see  Chapter  XII),  and  other  decorated  glass 
were  made  in  its  factories.  In  1609  Casper  Lehmann 
invented  engraving  on  glass  and  the  ancient  art  of 
cutting  was  revived.  In  1679  ruby  glass  was  intro- 
duced, and  the  action  of  hydrofluoric  acid  on  glass, 
which  made  etching  possible,  was  also  discovered  or 

applied  in  1670. 

The  industry  developed  rapidly  during  the  seven- 
teenth and  eighteenth  centuries.  Bohemian  glass  was 
not  so  delicately  fashioned  as  the  Venetian,  but  it  was 
of  purer  materials  and  therefore  clearer;  the  engraved 
glass  of  Bohemia  was  very  beautiful.  Flashed  glass 
(see  Chapter  XI)  was  much  used,  and  was  most  effec- 
tive when  engraved  or  cut  to  bring  out  the  contrast 
of  color  between  the  rich  ruby  or  violet  and  the  crystal 
beneath. 

Other  Varieties 

A  potash-lime  glass  was  made  by  the  Germans  in 


HISTORY  OF  GLASS-MAKING 


187 


imitation  of  the  Venetian,  but  the  colorless  variety  has 
always  been  known  as  Bohemian  glass. 

Toward  the  end  of  the  sixteenth  century  skilled  rock 
crystal  cutters  from  Milan  advanced  the  art  rapidly 
in  the  crystal  and  glass  cutting  factories  at  Prague, 
Bohemia. 

Early  Art  in  France 

France  had  some  glass  factories  as  early  as  the 
second  century ;  the  imperial  factory  at  Frontencennes 
was  supposedly  the  cradle  of  all  later  factories  in  Nor- 
mandy. The  glass  was  of  low  quality  and  of  a 
greenish  tinge.  During  the  Roman  occupation  the 
native  industry  died  out  and  Roman  glass  was  used 
instead.  The  characteristic  Roman  articles  —  vases, 
wine  bottles,  dishes,  etc.— are  found,  some  of^  them 
bearing  such  Latin  inscriptions  as  "Vale"  and 
"Salve."  French  museums  abound  in  specimens  of 
this  Roman  glass  which  has  been  unearthed  in  their 

districts. 

By  667  A.  D.,  foreign  workmen,  particularly  Greeks 
and  Romans,  began  to  revive  the  industry. 

The  city  of  Poitiers  abounded  in  wood  and  other 
materials,  and  ruins  of  ovens  and  melting  pots  mark 
sites  in  its  districts  where  glass  was  made. 

Normandy  was  the  first  province  to  grant  privileges 
to  glass  workers.     In  the  tenth  and  eleventh  centuries 


Ill 


1 88 


GLASSWARE  DEPARTMENT 


noble  families  followed  the  art,  and  **  gentlemen" 
from  Normandy  went  to  establish  factories  in  other 
cities.  In  the  time  of  St.  Louis  it  was  fashionable  to 
use  glass  on  the  table. 

While  the  Eastern  countries  excelled  in  mosaics,  to 
the  French  belongs  the  distinction  of  superior  work  in 
glass  painting  and  stained  windows.  Painted  glass 
windows  are  said  to  have  originated  in  the  School  of 
Limoges  about  Boo  a.  d.,  at  which  time  a  Venetian 
colony  was  established  there.  The  casting  of  plate 
glass  was  discovered  about  1693;  blowing  was  em- 
ployed up  to  this  time, 

The  town  of  Baccarat  in  France  has  since  1765  been 
the  center  of  plate  glass  and  crystal  factories  which 
are  world  renowned.  It  is  one  of  the  three  oldest 
glass  centers  in  western  Europe.  The  people  of  the 
district  all  work  in  the  factories  as  their  ancestors  have 
done  for  generations,  and  produce  a  glass  of  great 
beauty  and  delicacy.  In  1823  D'Artiques  established 
in  this  town  the  world  renowned  **  Crystalleries  de 

Baccarat." 

Many  European  palaces  and  public  buildings  are 
decorated  with  panel  or  plate  mirrors,  crystal  glass 
cases,  lamps,  and  vases  of  Baccarat  glass.  The  fac- 
tories excel  in  cut  and  engraved  pieces,  light  and  deep 
rock  crystal,  and  glass  with  rich  ornamentation  in  gold. 
One  odd  and  interesting  feature  is  the  glass  which  is 


HISTORY  OF  GLASS-MAKING 


189 


decorated  with  paintings  on  opaque  foundations  to  re- 
semble porcelain. 

English  Glass 

The  records  of  ancient  glass-making  in  England  are 
meager.  The  Druids  had  rudely  shaped  colored  beads 
which  they  used  as  charms  and  which  they  probably 
obtained  in  trading  with  the  Phoenicians,  who  went  to 
Britain  for  tin.  Most  of  the  glass  found  in  tombs  and 
recovered  cities  is  Roman,  however,  as  it  resembles 
that  of  Rome,  France,  and  middle  Europe.  Among 
such  relics  are  beads,  vases,  and  balls  of  crystal  glass, 
tear-vases  and  bottles  six  or  eight  inches  square. 
Glass  must  have  been  plentiful  even  in  Saxon  times, 
judging  from  the  quantity  found.  The  oldest  painted 
windows  in  England  are  those  of  Canterbury  (ii74)» 
which  date  from  the  Norman  period. 

Glass  tumblers  and  ale  and  beer  glasses  were  in  use 
on  the  tables  at  banquets.  In  a  drawing  on  an  Anglo- 
Saxon  calendar  in  the  British  Museum,  seated  figures 
are  shown  drinking  from  glass  cups  or  elongated  tum- 
blers of  hornlike  shape  and  blown  very  thin. 

Importation  rather  than  home  manufacture  seems  to 
have  been  encouraged. 

Growth  of  the  Glass  Industry  in  England 

In  1677  the  Duke  of  Buckingham  brought  glass- 


190 


GLASSWARE  DEPARTMENT 


makers  from  Murano  to  Lambeth,  England,  to  make 
crystal  vases,  looking-glasses,  and  other  articles.  In 
1685  political  disturbances  sent  French  glassmakers  to 
England,  so  that  in  1696  there  were  88  glass  factories 
making  chiefly  bottles,  mirrors,  and  ordinary  flint  glass 
tableware. 

The  distinction  of  perfecting  lead  or  flint  glass  be- 
longs to  England,  as  does  also  the  development  of  the 
art  of  glass  cutting.  Lead  glass  was  much  softer  and 
more  sparkling  than  the  lime  crystal  used  by  the  Ger- 
mans and  the  Bohemians,  and  the  English  cut  glass 
soon  surpassed  any  that  was  made  on  the  continent. 
London,  Bristol,  Birmingham,  Belfast,  Dublin,  and 
Glasgow  became  important  glass-cutting  centers. 

The  finest  specimens  of  English  glassware  belong  to 
the  period  between  1780  and  18 10.  Nearly  all  of  it 
was  tableware.  Stemware  of  all  kinds,  tumblers,  de- 
canters, saltcellars,  pitchers,  and  mugs  in  almost  end- 
less variety  are  now  gathered  by  the  collectors  of  this 
fine  type  of  glassware.  Some  glasses  were  thin  and 
delicate,  while  others  were  heavy  enough  to  pound  the 
table  without  injury  when  this  was  the  custom. 

Characteristics  of  English  Glass 

English  glass  shows  marked  individuality.  Bristol 
glass  is  especially  prized ;  but  all  of  it  is  interesting  and 
most  of  it  is  beautiful.     From  the  many  "  baluster  '* 


HISTORY  OF  GLASS-MAKING 


191 


stems  and  plain  bowls  of  the  earlier  types,  to  the  fine 
cutting,  engraving,  and  trailed  decoration  of  later 
manufacture,  one  may  trace  a  clear  line  of  develop- 
ment. Certain  peculiarities,  such  as  "  tears  "  or  bub- 
bles of  air  which  are  found  in  earlier  stems,  are  devel- 
oped by  a  process  of  drawing  out  and  twisting  into  the 
mysterious  air  twists  of  later  specimens. 

This  old  glass  has  the  clear  ring  of  the  lead  crystal 
and  much  of  it  is  beautifully  colored.  Greens,  from  a 
clear  apple-green  to  the  deep  color  of  the  emerald,  deep 
sapphire  blue,  amethyst,  and  old  rose  may  be  found 
among  these  old  glasses.  Political  history  is  also  writ- 
ten in  the  Jacobite  pictures  and  symbols  with  which 
some  of  them  are  engraved. 

English  tableware  lacks  the  delicacy  of  the  Vene- 
tian and  the  fanciful  decoration  of  the  Bohemian  glass, 
but  it  is  wonderfully  satisfactory  for  its  purpose. 


Chapter  XIX 

THE  GLASS  INDUSTRY  IN  THE  UNITED 

STATES 

Early  Experiments 

The  American  colonists  made  a  number  of  attempts 
to  produce  glass,  but  for  various  reasons  they  were  un- 
successful. A  few  English  glassmakers  came  to 
Jamestown  in  1608  and  tried  to  start  a  factory,  and 
early  records  mention  some  Italian  bead-makers. 
Wheeling  had  several  small  glass  houses  in  its  early 
history,  and  Pennsylvania  launched  several  enterprises 
but  all  were  shortlived.  There  was  a  lack  of  skilled 
workmen  and  the  sand  used  was  of  inferior  quality. 

There  was  no  general  development  of  the  industry 
until  about  the  middle  of  the  nineteenth  century.  The 
glass  that  was  produced  before  that  time  was  poor  in 
quality  and  crude  in  style.  The  better  grades  were  im- 
ported  from  England,  and  only  such  articles  as  com- 
mon bottles  and  heavy  table  glass  were  of  American 

manufacture. 
About  1840  attempts  were  made  to  produce  some 

192 


* 


UNITED  STATES  GLASS  INDUSTRY         1 93 

decorative  ware.  Bottles  were  made  in  sapphire  blue, 
emerald  green,  claret,  and  other  brilliant  colors ;  some 
were  shaped  like  log  cabins  or  cider  barrels,  and  the 
American  eagle  or  the  stars  and  stripes  were  used  as 
patriotic  decorations  for  tableware.  Opal  glass  was 
fashionable  for  candlesticks,  drawer  handles,  and  simi- 
lar articles. 

Pioneer  Glass-Making  Concerns 

The  foundation  of  the  glass  industry  was  laid  near 
Boston  when  the  New  England  Glass  Works  was  es- 
tablished, and  for  many  years  Boston  led  in  the  manu- 
facture of  flint  and  colored  glass  of  all  kinds. 

The  first  furnace  had  six  pots  and  forty  workmen, 
but  in  1865  five  furnaces,  of  ten  pots  each,  were 
operated,  five  hundred  workmen  were  employed,  and 
glass  valued  at  $500,000  was  produced  annually. 

Through  the  enterprise  and  liberal  policy  of  this 
company,  factories  for  making  glass  were  also  estab- 
lished in  other  parts  of  the  country.  Workmen  were 
brought  from  abroad,  and  capital  was  freely  expended 
to  make  the  industry  permanent. 

In  1855  William  L.  Libby,  who  was  then  a  confi- 
dential clerk  of  one  of  the  large  glass  importers  located 
in  Boston,  bought  the  glass  factory  of  his  employers 
and  for  twenty  years  enjoyed  an  enviable  reputation  in 
the  Massachusetts  industry.     Realizing  the  necessity  of 


194 


GLASSWARE  DEPARTMENT 


cheap  fuel,  however,  he  moved  to  Toledo,  where  first 
natural  gas  and  later  petroleum  were  available.  The 
Libby  Glass  Company  of  Toledo,  one  of  the  largest  of 
the  United  States  glass  manufacturing  concerns,  is  the 
result. 

Another  notably  successful  plant  was  started  in  1852 
by  Christopher  Dorflinger  of  Brooklyn,  with  a  capital 
of  $1,000,  for  making  glass  for  lamps  and  chimneys. 
The  discovery  of  petroleum  at  that  time  had  created  a 
great  demand  for  lamps,  and  his  furnaces  increased 
from  one  with  five  small  pots  to  four  in  1861  and  fif- 
teen in  1865.  During  that  year  he  moved  his  fac- 
tories to  White  Mills,  Pennsylvania,  where  he  now 
operates  one  of  the  largest  manufactories  of  cut  glass. 

Growth  of  the  Industry 

The  growth  of  the  glass  industry  in  the  United 
States  has  been  due  to : 

The  development  of  pressed  glass. 

The  invention  of  the  automatic  bottle  machine. 

The  improvements  in  furnaces. 

The  use  of  oil  and  gas  for  fuel. 

Pressed  Glassware 

The  manufacture  of  glass  by  means  of  metal  molds 
was  practiced  to  some  extent  in  England  and  America 
as  early  as  1834.     The  idea  of  pressing  the  molten 


UNITED  STATES  GLASS  INDUSTRY         195 

glass  into  the  required  shape  by  means  of  a  metal  core 
or  plunger  was  suggested  by  a  carpenter  in  Sandwich, 
Massachusetts,  and  taken  up  by  the  New  England  Glass 
Company  with  successful  results. 

The  perfection  of  this  type  of  glassware  was 
achieved  by  a  Pittsburgh  company  which  took  the  first 
prize  for  fine  pressed  glass  at  the  Paris  Exposition  in 
1867.  The  goblets  and  wine  glasses  produced  by  this 
company  could  hardly  be  distinguished  from  those 
made  by  blowing  and  cutting. 

Pressed  Lime  Glass 

Until  1864  pressed  glass  was  always  made  of  flint  or 
lead,  with  potash  and  saltpeter,  which  made  it  nearly 
as  expensive  as  cut  glass.  In  that  year  a  Wheeling 
glass  company  experimented  with  bicarbonate  of  soda 
and  lime,  and  succeeded  in  making  a  clear,  brilliant 
glass  at  about  one-third  the  cost  of  the  lead  glass. 

The  use  of  this  lime  glass  caused  a  rapid  growth  in 
the  pressed  glass  industry  in  the  West,  and  a  corre- 
sponding loss  to  the  flint  glass  manufacturers  of  the 
East,  who  could  not  compete  with  the  western  product 
on  account  of  its  lower  cost  of  production.  This  re- 
sulted in  the  disappearance  of  many  eastern  glass- 
works. 

Invasion  of  Foreign  Markets 

The  purity  of  color  and  the  excellent  design  of 


196 


GLASSWARE  DEPARTMENT 


American  pressed  glass,  together  with  its  comparative 
cheapness,  has  made  a  market  for  it  not  only  at  home 
but  also  in  foreign  countries,  both  in  Europe  and 
South  America. 

The  Owens  Bottle  Machine 

Another  discovery  which  revolutionized  the  bottle- 
making  industry  was  the  invention  and  perfection  of 
the  Owens  automatic  bottle  machine.  No  hand  opera- 
tions are  necessary  except  the  oiling  and  care  of 
the  machine.  It  makes  bottles  of  all  sizes  and  shapes, 
and  the  saving  of  labor  is  enormous.  In  19 14  between 
sixty  and  seventy  of  these  machines  were  in  use. 

Improvements  in  Furnaces 

There  were  no  important  changes  made  in  the  types 
of  glass  furnaces  used  until  1870,  when  increased 
competition  led  to  improvements  by  which  less  fuel 
was  made  to  produce  more  heat.  Larger  furnaces 
were  built,  many  of  them  holding  from  thirteen  to  fif- 
teen pots,  which  sometimes  contained  two  tons  of  glass 
each. 

The  use  of  natural  gas  for  fuel  gave  the  Middle 
West  its  greatest  advantages  over  other  sections  of  the 
country;  and  it  is  there  that  the  glass  industry  now  has 
its  center.  There  are,  however,  several  important 
manufacturing  centers  in  the  East,  among  them  Mill- 


UNITED  STATES  GLASS  INDUSTRY 


197 


ville  and  Glassboro,  New  Jersey ;  and  Bridgeton,  White 
Mills,  and  Philadelphia,  Pennsylvania. 

In  the  Middle  West 

In  western  Pennsylvania,  Carbondale  is  a  center, 
West  Virginia  and  Ohio  have  many  plants,  and  Toledo, 
Ohio,  makes  large  quantities  of  pressed  glass  as  well  as 
superior  blanks  for  eastern  cut  glass  factories. 

Muncie  and  Gas  City,  Indiana,  are  important  cen-. 
ters. 

Alton,  Illinois,  has  the  largest  flint  bottle  manufac- 
tories in  the  world,  4,500  workmen  being  employed. 
Chicago  and  some  small  towns  in  the  neighborhood 
have  numerous  plants  for  manufacturing  and  cutting. 

Pittsburgh,  Pennsylvania,  is  the  greatest  glass 
manufacturing  center  in  the  country.  It  produces  al- 
most every  type  of  glass.  In  1887  the  Pittsburgh  Plate 
Glass  Company  began  the  creation  of  what  is  now  the 
greatest  plate  glass  works  in  the  world. 

Pennsylvania  leads  as  the  glass-producing  state, 
with  West  Virginia  second.  The  large  deposits  of 
white  siliceous  sand  in  the  latter  state,  as  well  as  the 
abundant  supply  of  coal  and  natural  gas,  have  caused 
the  rapid  growth  of  the  industry. 

Today  the  United  States  leads  the  world  in  the 
manufacture  of  glass  and  glassware.  It  imports  some 
European  art  glass  and  glass  for  lenses,  but  exports 


198 


GLASSWARE  DEPARTMENT 


greater  quantities  of  machine-made  glassware  and  a 
large  amount  of  cut  glass. 

As  a  result  of  war  conditions,  the  trade  in  glass  be- 
tween this  country  and  South  America  has  been 
greatly  increased,  as  well  as  the  orders  from  European 
markets.  American  machinery  has  been  installed  in 
many  foreign  glass  manufacturing  plants. 

America  imports  glass  from  Austria  Hungary,  Ger- 
many, France,  England,  Belgium,  Italy,  The  Nether- 
lands, Sweden,  and  Japan.  In  Belgium  glass-making 
was  considered  the  national  industry  before  the  war. 


Chapter  XX 

SUGGESTIONS  TO  SALESPEOPLE 

Qualifications  for  Selling  Glass 

The  selling  of  glassware  requires  taste,  intelligence, 
and  imagination  on  the  part  of  the  salesperson.  While 
its  beauty  always  attracts  shoppers,  the  great  variety 
of  styles  and  designs  is  confusing.  Also  most  people 
fail  to  appreciate  the  quality  and  suitability  of  glass- 
ware with  the  same  discrimination  which  they  show  in 
choosing  clothing  and  other  practical  articles. 

A  knowledge  of  the  composition  of  glass,  of  the  dif- 
ference between  lead  glass  and  lime  glass,  and  of  the 
reasons  for  the  greater  cost  of  lead  crystal,  will  often 
sell  the  more  expensive  article.  A  few  remarks  re- 
garding the  manner  in  which  metallic  oxides  produce 
color  by  fusing  or  firing  make  an  interesting  point; 
and  even  the  "  ringing  "  of  a  crystal  goblet  with  its  sil- 
very tone  adds  to  the  value  and  attraction  of  the  article. 

Manufacture 

The  process  of  melting,  fusing,  and  forming  glass 
is  like  a  fairy  story  to  those  who  have  not  heard  it 

199 


200 


GLASSWARE  DEPARTMENT 


Blown  glass,  for  instance,  has  a  new  interest  for  cus- 
tomers when  they  learn  how  it  is  made.  Thus  a 
knowledge  of  the  various  processes  of  manufacturing 
the  different  kinds  of  ware  is  an  essential  part  of  the 
commercial  information  of  the  salesperson. 

The  salesman  should  understand  the  difference  be- 
tween cut,  semicut,  and  pressed  ware ;  acid  polish,  fire 
polish,    and   polishing  on   wheels.     Etching,   engrav- 
ing, and  carving  should  also  be  clearly  understood,  as 
well  as  the  difference  between  needle-etching  and  plate- 
etching.     Then  the  various  methods  of  applying  color 
and  gilding  are  not  only  interesting  but  important,  be- 
cause of  the  greater  durability  of  certain  forms  of 
decoration.     Articles  for  mere  ornament  need  not  be 
so  durable  as  those  which  are  to  be  in  constant  use.     It 
is  therefore  less  unfortunate  to  have  a  vase  with  a  dec- 
oration which  will  soon  wear  off  than  it  is  to  have 
water  glasses  with  the  same  defect. 

Other  Points  of  Importance  to  Customers 

An  acquaintance  with  modern  trade  centers,  both 
foreign  and  American,  will  give  interest  and  authority 
to  a  salesperson's  statements.  Thus  the  distinct  char- 
acteristics of  Venetian,  Bohemian,  Baccarat,  and  Bns- 
tol  glass  have  greater  meaning  when  arguments  can  be 
based  on  definite  information. 

Design  is  of  special  importance  in  glassware,  and  a 


SUGGESTIONS  TO  SALESPEOPLE 


20I 


cultivated  taste  is  first  of  all  necessary  that  one  may  be 
really  helpful  to  the  customer.  Then,  a  knowledge  of 
the  particular  designs  belonging  to  any  one  period, 
such  as  the  Colonial  or  the  Jacobite,  will  be  serviceable 
in  aiding  her  to  make  a  suitable  choice.  The  names  of 
the  designs,  especially  in  cut  glass,  should  be  learned 
and  properly  applied  as  they  always  attract  attention 
and  interest.  The  exclusiveness  of  a  design  gives  it  an 
added  value  to  many  customers,  while  standard  pat- 
terns of  recognized  merit  will  appeal  to  the  more  con- 
servative. 


Suitability 

It  is  estimated  that  two-thirds  of  the  cut  glass  sold 
is  intended  for  gifts.  Thus  the  salesperson  may  often 
make  a  return  or  an  exchange  unnecessary  by  learning 
something  of  the  purpose  for  which  the  article  is  in- 
tended and  the  possible  tastes  of  the  person  to  whom 
it  is  to  be  given.  These  must  often  be  mere  guesses, 
but  any  clue  may  save  some  blunders.  Thus,  when  a 
gift  is  to  be  made  to  one  who  "  has  everything,"  some- 
thing of  an  exclusive  design  is  more  likely  to  please 
than  a  commonplace  article  which  is  likely  to  be  a  du- 
plicate. 

Then,  too,  if  tactful  suggestions  are  made,  gift 
buyers  may  select  more  expensive  presents  and  be  bet- 
ter satisfied,  because  they  feel  that  they  have  the  right 


202  GLASSWARE  DEPARTMENT 

thing ;  while  on  the  other  hand  some  who  have  spent 
less  than  they  had  anticipated  are  thereby  made  per- 
manent customers. 

Arrangement 

Glass  is  usually  arranged  in  as  effective  a  manner  as 
possible,  so  that  its  decorative  value  may  be  thoroughly 
appreciated.  Single  pieces  as  well  as  sets  may,  how- 
ever, suffer  from  their  surroundings  and  not  be  seen  ^ 
to  the  best  advantage.  It  is  often  wise  to  place  them 
in  a  corner  where  they  have  no  more  brilliant  neigh- 
bors to  dull  their  beauty;  or  perhaps  there  may  be 
pieces  which  will  actually  help  to  set  them  off.  The 
value  of  proper  surroundings  is  nowhere  more  evident 
than  in  a  Glass  Department. 

Care 

The  glass  on  sale  in  a  department  should  always  be 
spotless  and  shining.  The  salesperson  may  give  help- 
ful information  to  customers  as  to  the  care  of  their 
purchases. 

Cleaning 

The  washing  of  glassware  has  much  to  do  with  its 
beauty.  Glass  is  slightly  acted  upon  by  alkalies; 
therefore  strongly  alkaline  soaps  or  washing  powders 


SUGGESTIONS  TO  SALESPEOPLE 


203 


will  dull  or  scratch  the  surface.  Water  at  the  boiling 
point  will  also  affect  the  polish. 

Glasses  or  pitchers  which  have  contained  cream  or 
milk  should  be  rinsed  with  lukewarm  water  softened 
with  a  little  soda  before  being  washed  with  the  other 
pieces,  as  otherwise  all  the  glass  will  have  a  clouded 
appearance.  Water  bottles  or  pitchers  which  have  a 
deposit  of  lime  on  the  inside  may  be  cleansed  by  put- 
ting in  tea  leaves,  covering  them  with  vinegar,  and 
shaking  the  bottles.  A  teaspoon ful  of  hydrochloric 
acid  in  a  little  water  will  also  remove  this  deposit. 
The  bottle  should  be  rinsed  immediately. 

Carbonate  of  ammonia  causes  flint  glass  to  become 
brittle  so  that,  it  will  easily  brealc  and  pieces  will  fall 
off. 

Glass  should  be  washed  in  clean,  warm  (not  hot) 
water,  with  a  little  white  soap.  Some  housekeepers 
believe  that  it  is  cleaner  when  rinsed  in  water  which 
contains  no  soap;  others  rinse  in  slightly  soapy  water 
and  dry  and  polish  on  hot  towels. 

Glass  is  often  broken  by  pressure  from  the  dish 
cloth  or  dish  mop  when  washing  the  inside.  The  fol- 
lowing suggestion  is  a  good  method  for  delicate  cups 
or  glasses : 

"  Have  enough  water  in  the  dishpan  so  that  when 
the  glass  or  cup  is  turned  upside  down  it  will  be  en- 


204  GLASSWARE  DEPARTMENT 

tirely  full  of  water;  now  lift  the  glass  quickly,  still 
keeping  it  upside  down  and  being  careful  not  to  tip  it. 
It  will  remain  full  of  water  until  it  reaches  the  surface, 
when  the  rushing  in  of  air  will  force  the  water  out  so 
suddenly  that  it  will  carry  all  food  particles  with  it. 
This  is  an  excellent  method  for  washing  sherbet  and 

lemonade  glasses."  ^  ,     .  ,i 

A  writer  in  "  Crockery  and  Glass  "  gives  the  follow- 
ing suggestions  for  cleaning  cut  glass : 

"  First  make  a  warm  soap-suds  and  wash  the  pieces 
with  an  old  tooth-brush  which  will  fit  into  the  curved 
shapes  and  cut  figures.  Rinse  in  clear,  warm  water 
and  wipe  with  a  linen  towel.  After  this  polish  with  a 
warm  towel  and  set  in  a  box  of  sawdust  for  a  few 
hours.  The  sawdust  absorbs  the  moisture  in  the  in- 
cisions  not  reached  by  the  towel,  and  also  heightens  the 
polish.  When  taken  from  the  sawdust  rub  with  a  piece 
of  tissue  paper  and  the  glass  will  sparkle  like  crystal. 

Things  to  be  Avoided 

Glassware  should  not  be  arranged  in  piles  as  it  is 
heavy  and  brittle.     Pieces  are  apt  to  be  chipped  off 
and  sometimes  the  lower  pieces  in  the  pile  are  cracked 
by  the  mere  weight  of  those  above.     Such  arrange- 
ment is  particularly  unsuitable  for  cut  glass. 

1  From  Choice  and  Care  of  Utensils,  by  Ida  S.  Harrington.  Farm  House 
Scries  No.  5.  Cornell  Reading  Courses. 


SUGGESTIONS  TO  SALESPEOPLE 


205 


Glass  should  be  protected  against  extremes  of  tem- 
perature, such  as  cold  storerooms  or  overheated  chests. 
Very  hot  or  very  cold  water,  chilled  or  hot  food,  may 
cause  it  to  crack.  It  should  be  tempered  or  warmed 
before  putting  in  hot  liquids,  or  cooled  before  filling 
with  ice-cream. 

When  boiling  water  or  boiling  syrups  are  to  be 
poured  into  glass,  the  danger  of  breakage  is  lessened 
by  putting  in  a  silver  spoon. 

Glass  is  very  little  affected  by  moisture,  air,  or  light. 
Even  after  being  buried  in  the  earth  for  many  years 
the  only  deterioration  is  an  oxidation  of  the  surface 
which  shows  in  iridescent  colors  as  in  antique  glass- 
ware. Therefore  with  proper  care  and  handling  glass 
may  be  considered  almost  indestructible. 


Chapter  XXI 

CLASSIFICATION  OF  STOCK  OF  A 
TYPICAL  GLASSWARE  DEPARTMENT 


A. 


B. 
C. 


Divisions 

Tableware 

1.  Cut  Glass 

2.  Pressed  Glass 
Toilet  Sets 
Decorative  or  Art  Glass 


A  —  Tableware 


I.  Articles  in  Sets 
Water 

Grape  Juice  or  Iced  Tea 
Wine,  Cordial,  Liqueur,  Cocktail 
Sherbet 
Grapefruit 
Punch  or  Lemonade 
Finger-bowls 
Berry 
Coasters 

Mayonnaise  or  Whipped  Cream 
Almond  or  Relish 
Sugar  and  Cream 

Flower 

206 


CLASSIFICATION  OF  STOCK 


207 


2.  Single  Articles 
Pitchers 
Jugs 

Tankards 
Decanters 
Carafes 
Water  Bottles 

Cruets  for  Oil,  Vinegar,  Catsup 
Bowls 

Fruit 

Punch 

Salad 

Berries 

Whipped  Cream 

Rose 

Crackers 
Compotes  or  Compotiers 
Nappies 
Bonbon  Dishes 
Plates 
Plateaux 
Trays 

Ice-cream  Platters 
Sandwich  Plates 
Celery  Trays 
Jam  and  Marmalade  Jars 
Sugar  Bowls 
Sugar  Sifters 
Sugar  Trays 
Salt  and  Pepper  Shakers 
Saltcellars 
Spoon  Holders 
Dinner  Bells 
Toothpick  Holders 


208  GLASSWARE  DEPARTMENT 

Knife  Rests 

Syrup  Jugs 

Fern  Dishes 

Punch  Ladles 

Salad  Forks  and  Spoons 

Iced  Tea  Spoons 

Baking  Dishes 

Ramekins 

Cake,  Pie,  and  Bread  Pans 

Casseroles 

3.  Materials 
Sand 
Lead 
Lime 
Potash 
Soda 

Metallic  Oxides 
Gold 
Silver 
Enamel 
Rock  Crystal 

4.  Manufacture 

Cut 

Carved 

Blown 

Pressed 

Molded 

Rolled 

5.  Decoration 

Etching 
Gilding 
Enameling 
Engraving 


CLASSIFICATION  OF  STOCK 

Frosting 
Painting 
Silver  Deposit 
Body  Color 

Single  Color 

Iridescent  Colors 

Fire  Colors 

6.  Kinds 

American 

English 

French 

Swedish 

Bohemian 

B  — Toilet  Sets 

• 

1.  Articles 

Night  Sets 

Guest  Sets 

Toilet  Bottles 

Toilet  Sets 

PuflF  Boxes 

Pin  Trays 

Comb  and  Brush  Trays 

Jewel  Boxes 

2.  Materials,  Manufacture,  Decoration,  Kinds 

See  3,  4,  5,  6,  under  A 

C  —  Decorative  or  Art  Glass 

I.  Articles 
Vases 

Candlesticks 
Candelabra 


209 


., 


f  1 


210  GLASSWARE  DEPARTMENT 

Flower  Bowls 
Flower  Baskets 
Card  Holders 
Clocks 
Pin  Trays 

Comb  and  Brush  Trays 
Jewel  Boxes 
3.  Materials,  Manufacture,  Decoration 
See  3, 4,  5>  under  A 

3.  Kinds 

Same  as  A-6 
Venetian 
Bohemian 
Tiffany 


Appendix 

Books  for  Reference 

Glass  Manufacture,  Walter  Rosenhain.    Van  Nostrand,  $2 
Principles  of  Glassmaking,  Powell.    Geo.  Bell  &  Sons  (Lon- 
don) 
Glass  in  the  Old  Worid,  Wallace  Dunlop.    Field  &  Tuer 

(London) 
Wonders  of  Glassmaking,  Alexandre  Sauzay.     Scribner,  $1 
Laboratory   Guide  of  Industrial   Chemistry,   Rogers.    Van 

Nostrand,  $1.50 
The  Glaziers  Book,  E.  L.  Raes.    Maclaren  &  Sons  (London) 
English  Table  Glass,  Percy  Bate,  B.  T.  Batsford.    Scribner, 

$2.50 
Decorative  Glass  Processes,  Arthur  Duthie.    Van  Nostrand, 

$2 
The  Lure  of  the  Antique,  W.  A.  Dyer.     Century,  $2.40 
Marietta,  Marion  Crawford.    Macmillan,  $1.50 
Crockery  and  Glass  Journal,  Trade  Journal 
International  Studio,  Special  articles 
J.  P.  Morgan  collection 
Development  of  Cut  Glass  Industry  in  the  U.   S.,  W.  F. 

Dorflinger 
American  Glassware,  Old  and  New,  E.  A.  Barber.    Keramic 

Studio  Pub.  Co.,  $1 
Art  of  Glass,  Neri 
Notes  on  the  History  of  Glassmaking,  Alexander  Nesbit, 

Catalogue  of  Slade  Collection  of  Glass,  Felix 
Reminiscences  of  Glassmaking,  Deming  James  (only  print) 
Principles   of  Glassmaking,   Powell,  Chance,   Harris.    Geo. 

Bell  &  Sons  (London) 


211 


i  m 


INDEX 


Abbb,  E.,  144 

Acid  Polishing,  44,  60 

Aeroplane  Windshields,  51 

Alkalies, 

marine  plants  near  Venice,  i8a 

potash  and  soda,  12 
ALin^iNUM,  16,  141.  143 
Alundum.  58 
Amalgam  Mirrors,  79 
Amber  Glass,  103 
Amphora,  Roman,  179 
Ampullas,  Roman,  179 
Annealing.  42,  184 

process,  42 
Aquamarine,  120 
Arsenic,  16,  141 

Art  Glass,  Meaning  of  Term.  102 
Automatic  Bottle  Machine,  49, 196 
aventurin,  184 
Aviators'  Goggles. 

B 

Baccarat,  38,  188 

Banding  Gold,  97 

Barium,  16, 17,  143 

Bastie,  de  la,  44 

Batch,  20,  21,  32,  33 

Battledore,  36 

Bauxite,  58 

Beads,  Glass,  51,  i74i  i84i  189 

BiBERON,  III 

Biguglia,  C.  Pibtro.  X83 
Black  Glass,  104 
Blank  Molds,  49 


Blanks,  35,  5S.  57,  60,  98 
Blower's  Tools, 

battledore,  35 

blowpipe,  35 

glass  blowpipe,  35 

measuring  stick,  36 

pincers,  36 

shears,  36 

spring  balance.  36 

tongs,  36 

working  rod.  35 
Blowing, 

glass,  35 

automatic  machines,  38 
bottles,  47 
cut  glass  blanks,  55 
shaping  stemware,  73 
Venetian,  109 

iron,  35.  36 
Blowpipe,  35,  36,  37t  no 
Bohemian  Glass, 

characteristics,  114 

history,  115,  186 

medallions,  115 

methods  of  ornamentation,  1x4 

sources,  114.  186 
Bonbon  Dishes,  78 
Borax.  16,  17 
Boric  Acid,  143 
Bottle  Glass.  45, 60 
Bottles. 

ancient,  180 

blown.  47 

made  by  automatic  machines,  47*  49 

molded,  47.  48 

tear,  178, 185, 189 


213 


INDEX 


INDEX 


214 

Bowls  and  Dishes,  77 
Brashkar,  John  A.,  146 
Bullbt-Proof  Glass,  so 


Calcitb  Glass,  104 

Cameo  Glass,  hi 

Candelabra,  124,  131.  I3a 

Candlesticks,  123,  131.  132.  138 

Candle  Protectors,  132 

Canes,  Glass,  ho,  hi 

Carving  Glass,  69 

Ceramo  Crystal,  s* 

Chalk,  16 

Chandeliers,  132 

Chemical  Compositions  of  Glass, 

143,  148 
Cobalt,  141 
Collections,  Glass  (See  "Museum 

collections") 
Colonial  Designs,  88,  124,  132 
Colored  Glass,  17,  52. 103. 106,  no, 

117 
Coloring  Materials,  17.  102.  i^S. 

"8  .      „ 

Colors       (See     also    "Bohemian, 
"Egyptian,"     "English,"    "Ro- 
man,"   "Tiffany,"    "Venetian," 
etc.,  glass") 
pot  metal,  US 
Compotes  and  Sweetmeat  Dishes, 

77 
CONSTANTINE,  1 82 

Constantinople,  182 
CoRDY  OR  Wavy  Glass,  45 
Cragleith,  58 
Crown  Glass,  i47,  148,  iSS 
Cruets  and  Bottles,  77 
C  Tank,  31 
CuLLET,  22,  32, 142 
Cut  Glass, 

American,  62 

blanks,  SSt  S9 


215 


Cut  Glass — Continued 
characteristics,  S3 
cut  rock  crystal,  63 
cutting  wheels,  S6 
designing.  55 
differences    between    English    and 

American,  62 
English  patterns,  62 
figured  blank  glass,  S9 
floral  patterns,  63 
judging  values,  61 
labor  cost,  57 
machines  for  cutting.  61 

materials.  54 
miter  cuts,  62 
polishing,  S8,  60 
process.  54 
roughing.  57 
smoothing,  S8 
standard  patterns.  88 
stone  engraving.  56 
tracing  the  design,  56 


D'Artiques,  M,  188 
Daylight  Glass,  136 
Decolorizers,  9.  16,  141 
Decoration, 

acid-etching,  68 

colored,  96 

methods  of  ornamenting  glass  sur- 
faces, 96 

Design,  *    •  1     q- 

appropriateness  to  use  of  article,  8S 

cut  glass,  86 

miter  cuts,  62,  86,  87 
engraved  patterns,  89 
form  or  shape.  83 
f xmdamentats .  83 
good,  92 
pattern, 

center  of  interest,  90 

composition  of  line,  9X 


Design — Continued 
pattern — Continued 

elements  of,  90 

gradation,  91 

laws  of,  89 

radiation,  91 

repeated  patterns,  90 

symmetry,  91 
shape,  importance  of,  83 

cut  and  blown  glass  articles,  84 
use  of  color,  92 
Drawn  Stemware,  7  if  73 


B 


Egyptian  Candlesticks,  131 
Egyptian  Glass, 

beads,  174 

colors,  174 

first  evidence  of  domestic  use,  I73 

glass  porcelain,  17S 

imitation  stones  and  jewelry,  174 

mosaics,  174 

transparent  blue,  174 
Electric  Light,  125, 126, 13S.  136, 137 

daylight  lamps,  136 

fixtures,  I34f  I3S 

incandescent  lamp,  invention,  I39 

shadowless  lights,  136 
Electroplating  Silver  Deposit,  99 
Embossing,  69 

EiNAMELS    AND    SpRAYED-ON    MeTAL, 

'  129, 130 
Enamel  Painted  Glass,  156,   158, 

160 
English    Glass     (See    also    "Cut 
glass") 
ancient,  189 

centers  of  cutting  industry,  190 
colors,  191 
Druids,  189 
early  factories,  190 
individuality,  190 
perfection  of  flint  or  lead  glass,  190 


English  Glass — Continued 

political  history,  191 

tableware,  191 
Engraved     Glass,     Methods     of 

Decoration,  66 
Engraving  Glass,  66 
Etched  Glass, 

needle-etching,  67 

plate-etching,  68 

sand-blast  etching,  68 


F 


Favrile  Glass,  ii7i  120 
Field  Glasses,  147 
Figured  Blank  Glass,  59 
Figured  Rolled  Plate,  152 
Filigree  Glass,  hi 
Filling  Hole,  29 
Fining,  33.  i43 
Finishing  Processes, 

annealing,  42 

gathering,  34 

molding,  41 

polishing,  44 

pouring,  34 

sadling,  34 

varieties  of  kilns,  43 
Fire  Polish,  44.  46 
Firing  Smv^R  Deposit,  99 
Flashed  Glass,  106,  114.  is6 
Flint,  6,  10 

Flint  Glass,  h,  i8s,  190 
Floating  Compartments,  31 
Floral  Cut,  60 
Flutes,  62 
Fluxes,  12,  33 
French  Candlesticks,  132 
French  Glass,  D'Artiques,  x88 

Baccaret  crystal  factories,  188 

D'Artiques,  188 

Frontencennes,  187 

painted  windows,  188 

plate  glass  casting,  188 


2l6  INDEX 


INDEX 


Fringes,  6a 
Frit,  a 2,  33 
Frontencennbs,  187 
Frostbd  Glass.  69,  m 
Frosting,  63, 69,  xii 
Furnaces,  Glass. 

ancient  Venetian,  z8a 

calcar,  31 

construction,  23 

C  tank,  3X 

fire  clay,  37 

fuels.  34 

kinds,  33 

manufacture  of  pots,  a8 

pot  furnaces,  25 

tank  furnaces,  ag 


Gas, 

fixtures,  13a.  Z33,  Z34 

history,  I39 

illuminating,  13$,  139 

lamps,  126 

mantles,  I34t  I39 
Gas  Mask  Lenses,  51 
Gathering  Glass,  34^  37*  3S.  4it  48. 

55,  72,  106 
Gems  or  Seals,  105 
Gilding, 

gold  banding,  97 

gold  leaf.  97 

gold  resist,  96 
Glass, 

characteristica, 
beauty,  3, 4 
durability,  3,  4 
utility.  3 

divisions  according  to  composition. 
a 

nature  of  (See  "  Nature  of  glass") 
Glass  Balls.  Ancient  Use,  x79 
Glass  Industry  in  U.  S., 

early  experiments,  19a 


Glass  Industry  in  U.  S. — Continntd 

growth  of,  194 

improvements  in  furnaces,  196 
invasion  of  foreign  markets,  19S 
pioneer  concerns,  193 
PitUburgh  and  the  Middle  West, 

197 

pressed  lime  glass.  '95 
Glass  Pavements,  5a 
Glass  Trays,  78 
Glassware, 

display,  x 

divisions  of  department,  a 
Glory  Hole,  44 
Gold,  Liquid  Bmght,  94 
Gold-Leaf,  95 
Gold  Luster,  119 
Green  Glass,  103 
Gypsum,  16 


Heat  Resisting,  or  Oven  Glass,  si 
High  Color,  45 

History  of  Glass- Making  (See  also 
"Bohemian,"  "Egyptian," 

"English,"  "French,"  "Roman,* 
and  "Venetian  Glass") 

ancient  varieties,  X78 

Assyrian.  I7S 

Bohemian,  186 

"  Christian  glass."  i8x 

early  art  in  France,  187 

Egyptian,  I73 

English,  189 

Grecian,  177 

modem  development,  185 

oriental  countries,  I75 

Persian.  176 

Pompeii  and  Herculaneom,  z8o 

Roman,  177 

Spanish.  185 

Theban,  works  of  art,  X7S 

Venetian,  i8z 


217 


Hobnail  Patterns,  63,  88 
Horseshoe  Flame,  29 
Hydrofluoric  AaD,  67 


Ice  and  Butter  Tubs,  77 
Imitation  Gems,  u,  sa,  i7S,  178 
Incandescent  Lamps,  134,  135,  136 

invention,  I39 
Insulation.  Glass  for,  so 
Iridescence, 

antique  glass,  119,  I79 
modem  glass,  104, 105,  118 


Jars,  77 

Jena  Glass,  Laboratory,  x44 


Kelp,  ii,  I3t  X4 
Kilns.  43 
intermittent,  43 


Laboratory  Glass, 

development  in  U.  S..  tests.  149 

Jena  glass,  149 

materials,  X49 

resistance  to  acids,  alkalies,  shock, 
etc.,  148,  149 

thermometers,  ISO 

uses,  148 
Lacquering,  98 
Ladling,  34.  35.  "8 
Lamp  Chimneys,  128 
Lamp  Stands,  138, 138 
Lamps,  135 

adjustable,  ia7 

electric,  126.  ia7 

floor,  138 


Lamps — Continued 

gas,  126 

history,  137 

oil,  125,  136,  139 

portable,  126 

student,  126 

table,  127 
Lampshades,  139 

glass,  130 

metal,  129 

parchment,  130 

porcelain,  130 

textile,  1:^0 
Lanterns,  123 

automobile,  133 

feast  of,  139 

Chinese  and  Japanese,  X38 

history,  138 

oriental,  X33 

ships',  X33 
Laticblla  Glass,  112 
Lead,  6,  11,  15,  i7.  18,  sa,  54 
Leaded  Lights, 

construction,  154 

kinds  of  glass  used,  I55 
Lbhmann,  Caspar,  114.  186 
Lehrs,  4a 

continuous,  43 
Lens  Grinding, 

difficulty,  145 

Yerkes  and  Mt.  Wilson  telescopes, 

X4S 
Lenses, 
automobile,  sx 
compound,  X47t  X48 
concave,  X47 
convex, 147 
cylindrical,  X47 
eyeglass,  X47 
gas  mask,  sx 
lighthouse,  X47 
magnifying,  147 
microscope,  147 
mirror,  80,  X46 


21 8  INDEX 


INDEX 


219 


Lbnsbs — Continued 

periscope,  145,  146 

photograph,  146,  147 

spherical,  147 

testing,  148 
LiBBiG,  J.,  VON,  79 
Lighting, 

daylight  glass,  136 

fixtures.  135,  133 1  I3S 

illuminated,  135 

indirect,  13S 

semi-indirect,  I3S 
Limb,  6,  11,  is,  59f  zo8 

chalk,  16 

crystal,  59 

gypsum,  16 

limestone,  16 
Limestone,  16 
Limoges.  School  of.  188 
Liquid  Bright  Gold,  96 
Low  Color,  45 


Machines,  Glass-Cutting,  61 
Magnesia,  16 
Mahogany  Glass,  103.  104 
Manganese,  141 
Manufacture  of  Glass, 

fusing  and  fining,  33,  3a 

mixing  the  batch,  3i 

preparation  of  sand,  30 
Marver,  37 
Marvering,  37.  no 
Mat  Finish,  63 

Materials,  Glass.  5,  54.  108,  X14. 
X18,     176     (See    also     "Lead." 
"Lime,"      "Potash,"     "Sand," 
"Soda,"     and     "Coloring     ma- 
terials") 
Mazarin  Blub,  i30 
Mazda  Lamp,  137 
Metal,  Glass,  34.  46,  93 
Metallic  Lustb&s,  105 


Microscope  Lenses,  147 

MiLLEFioRi  Glass,  ii3 

Mirrors,  79.  83,  130, 184.  188,  190 

amalgam.  79 

platinum.  81 

silvered,  80 
Moil.  39 
Mold.  39.  4X 

blank.  49 

finishing,  49 

measuring,  48 

neck,  49 
Molding,  41.  48 
Moonlight  Iridescent  Glass,  104 

Mosaic  Glass,  hi 
Mosaics.  51 

Mt.  Wilson  Telescope,  146 
Mulberry  Glass,  103 
MuRANO.  43.  108,  i8a 
MuRRiNE,  178 

Museum  Collections  of  Glass,  6s, 
lis,  174.  I7S.  178,  180,  186,  189 


Nature  of  Glass, 
a  neutral  salt,  8 

artificial  mineral  combination,  S 
different  from  precious  stones,  6 
possibilities  for  artistic  treatment, 

95 
viscosity,  5.  34 
Needle-Etching,  67 
Nero,  a  Glass  Collector,  i77 
Ninbvah  Vasb,  175 


Oil  Lamps,  135.  i36,  138,  139 
Olives,  63 

Opaline  or  Opal  Glass.  103 
Opaque  and  Sbmiopaqub  Glassxs, 

17 


Opbra  Glasses,  147 
Optical  Glass, 

American,  I45 

during  World  War,  14S 

furnaces  and  crucibles,  143 

Jena  glass,  I44 

manufacture,  143 

materials.  142 

power  of  resistance,  143 

requirements.  140 

veins  or  striae,  141.  I44.  i4S 
Ovens  (See  "Furnaces,"  "Kilns") 
Owens    Automatic     Bottle     Ma- 
chine, 49.  146 


Painting  and  Enambling.  97 
Palettes,  51 
Patera,  179.  181 
Pavements,  Glass,  52 
Peacock  Glass,  118 
Pearl  Luster,  104 
Pearlash,  II,  X3 
Pitchers.  77.  8s.  87 
Plate  Etching,  68 
Plate  Glass.  151 

casting,  188 

figured,  153 

polished,  153 

rolled,  15  X 
Plateaux,  81 
Plunger,  39.  40.  48 
Polished  Rolled  Plate,  xsa 
Polishing,  44 

acid,  44.  60 

cut  glass,  58 

mirrors,  80 

silver  deposit,  xoo 
PoNTiL,  48,  73  (ape  also  "Punty") 
Portland  Vase,  180 
Pot  Metal  Colors,  iiS 
Potash,  6,  to,  X3,  54f  80 

American,  13 


Pouring,  34>  35.  So 
Prague,       Glass-Cutting       Fac- 
tories, 187 
Precious  Stones.  Formation, 

different  from  glass,  6 

imitations  in  glass,  n,  53 
Pressed  Glass,  38.  40,  44.  46 
Pressing  Glass,  38,  194 
Prisms.  63,  133,  146,  i47 
PuNTY,  38,  73  (See  also  "PontU") 


Quartz, 
crystallized  silica,  xo 

flint,  10 

rock  crystal,  64 


Red  Lead,  is 
Resist,  67.  68.  70 

gold.  96 
RoBiNET,  M.,  38 
Robinet  Pump,  38 
Rock  Crystal. 

ancient  lens,  176 

collections.  65 

cut,  63 

cutters.  187 

for  lenses,  147 

genuine,  64 

works  of  art,  64 
Rolled  Plate  Glass.  SX.  ^SX 
Roman  Glass, 

amphora  and  ampullas.  Z79 

"Christian"  glass,  i8x 

color  effects.  178 

crystal,  179 

factories,  X77 

many  designs,  178 

patera,  179 

Portland  vase,  x8o 


220  INDEX 


roughbrs,  57 
Roughing,  57 
Russian  Candlesticks,  131 

s 

Safety  Glass,  50 
Salespeople,  Suggestions, 

arrangement  of  stock,  203 

care,  203 

cleaning  glassware.  203 

knowledge  of  manufacture,  199 

points  of  importance  to  customers, 
200 

qualifications  for  selling  glass,  I99 

suitability,  201 
Salt-Cake,  14 
Saltpeter,  xi,  is 

Chile,  14 
Samian  Red,  118 

Sand,  6,  7.  ".  54,  "4. 176 

preparation,  20 

sand  beds,  9 

sandstone,  10 
Sand  Blast  Etching,  68 
Sargon  Vase,  17s 
ScHOTT,  O.,  144 
Seaweed,  ii,  14.  176 
Seedy  Glass.  45 
Semicut  Glass,  60 
Sets. 

almond,  76 

bedroom  and  toilet,  76 

berry,  75 

finger-bowl,  75 

flower.  76 

grapefruit.  75 

grape-juice,  75 

iced  tea,  75 

mayonnaise  or  whipped  cream,  76 

punch  and  lemonade.  75 

sherbet.  75 

sugar  and  cream,  76 

water.  74 

wine,  75 


Shadowless  Lights,  136 

Sheet  Glass,  151 

SiDON,  Invention  of  Mirrors,  X7f 

Silica,  6.  10, 11,  54t  64 

Silver  Deposit,  Glass,  v8 

engraving,  loi 

original  process,  loi 

process  of  manufacture,  98 
Silver  Nitrate,  80 
Silver  Stain,  105.  156.  167 
Silvering  Mirrors,  80 
Smoothing, 

cut  glass.  58 

silver  deposit.  100 
Soda.  ii.  12.  14,  108 

Chile  saltpeter,  14 

salt-cake,  14 
Soda- Ash,  14 
Splits,  62 
Spun  Glass,  50 
Stained  Glass.  105.  X59 

antique,  161.  i6a 

definition,  159 

design.  iS9.  160.  i6x,  i6s,  170 

enamel  painted.  z6o 

flashed  glass,  164 

opalescent.  160 

plated,  160 

silver  stain.  167 

tyi)es,  160 

Venetian,  antique,  164 
Stars.  62 
Stem  Variations,  73.  xgx 

Stemware,  71 

shapes. 

bell-shaped,  73 

drawn,  73 

ovoid,  73 

Btraight-sided,  73 

variety  of,  la 
shaping,  72 
the  "boss,"  72 
Stone  Engraving,  56,  98 
Stony  Glass,  45 


INDEX 


221 


Strass,  IX 

Strawberry  Diamonds,  6a 

Striae.  141.  X44 


Table  Reflectors,  8x 

Tableware.  71 

Tankards  and  Jugs,  77 

Tazza,  III 

Tear-Bottles  or  Tear-Vases,  178 

185,189 
Tears,  in  Glass,  19X 
Tel-al-amana,  120 
Telegraph  Poles,  Glass,  50 
Telescope  Discs,  80 
Telescope  Lenses,  Difficulty  of 

Making,  146 
Thermometers,  150 
Tiffany  Glass,  117.  I30 

characteristic  colors,  117 

meaning  of  Favrile,  120 
Trailing,  70,  73. 105,  109 
Transparency  of  Glass, 

limited  by  coloring  materials,  14X 
Tumbler,  Evolution  of,  37 
Tumblers,  74. 190 


Vase, 

Portland,  180 

Sargon.  I75 
Vases, 

lamp,  128 

ornamental,  132 

table,  7,  122. 

varieties,  121 

Venetian  Glass, 

American  reproductions,  93,  XI3 
beauty  of  design  and  color,  92.  X07, 

XI3 


Venetian  Glass — Continued 

composition,  108 

curious  shapes,  108 

examples,  113 

mirrors,  184 

process  of  formation,  109 

tools.  183 

varieties,  in 
Verre  de  Soie,  103.  X04 

w 

Water  Bottles,  75 
White  Glass,  105 
Window  Glass,  151,  i5S,  IS9 
Window  Glazing,  152,  165 
Windows, 

antique  glass,  161 

casement,  IS3 

design  for  stained  glass,  X70 

double  hung,  152 

eflEect  of  finished  window,  169 

enamel  painted,  160 

English  casement,  154 

French.  IS3,  188 

opalescent,  x6x 

stained  glass,  IS9.  X64 
Wire  Glass,  51 
Wisteria  Glass,  103 
Working  Hole,  29,  10,9 
Working  Rod,  36 


Ybrkbs  Telbscopb,  X46 

Z 

Zinc,  17 

Zinc  Oxidb,  X43 


M&H  9^^ 


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